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Agricultural  Engineering 


Farm  Science  Series 


Agricultural  Engineering 

By  J.  B.  Davidson,  Iowa  State  College  of 
Agriculture  and  Mechanics  Arts 

Field  Crops 

By  A.  D.  Wilson,  University  of  Minnesota 
and  C.  W.  Warburton,  U.  S.  Department  of 
Agriculture 

Beginnings  in  Animal  Husbandry 

By  C.  S.  Plumb,  Ohio  State  University 

Soils  and  Soil  Fertility 

By  A.  R.  Whitson,  University  of  Wisconsin 
and  H.  L.  Walster,  University  of  Wisconsin 

Popular  Fruit  Growing 

By  S.  B.  Green,  University  of  Minnesota 

Vegetable  Gardening 

By  S.  B.  Green,  University  of  Minnesota 
{OTHER  BOOKS  IN  PREPARATION) 


Agricultural  ;  Engineering 

A  TEXT  BOOK 

FOR 

STUDENTS  OF 

SECONDARY  SCHOOLS  OF  AGRICULTURE 

COLLEGES    OFFERING   A   GENERAL 

COURSE  IN  THE  SUBJECT 

AND  THE 

GENERAL  READER 


BY 


J.  BROWNLEE  DAVIDSON,  B.  S.,  M.  E. 

Member  American  Society  of  Agricultural  Engineers 

Member  American  Society  of  Mechanical  Engineers 

Member  Iowa  Engineering  Society 

Professor  of  Agricultural  Engineering,  University  of  California 

Joint  Author  "Farm  Machinery  and  Farm  Motu's" 


REVISED 


COPYRIGHT,  1913 

Bt 

WEBB    PUBLISHING    COMPANY 

St.  Paul,  Minn. 

All  Rights  Reserved 

W-5 


PREFACE 

Believing  that  the  study  of  Agricultural  Engineering 
should  fill  an  important  place  in  the  training  of  the  young 
man  who  would  make  farming  the  object  of  his  Ufe's  work, 
the  author  has  attempted  to  furnish  in  this  volume  an  aid  in 
supplying  this  part  of  his  training.  The  application  of 
agricultural  engineering  methods  to  agriculture  should  not 
only  raise  the  efficiency  of  the  farm  worker  but  should  also 
provide  for  him  a  more  comfortable  and  healthful  home. 

This  volume  has  been  written  primarily  as  a  text  for 
secondary  schools  of  agriculture,  and  for  colleges  where  only 
a  general  course  can  be  offered.  Claim  is  not  made  for 
much  new  mateiiai  concerning  the  subjects  discussed;  but 
rather  an  attempt  has  been  made  to  place  under  one  cover 
a  general  discussion  of  agricultural  engineering  subjects 
which  hitherto  could  not  be  secured  except  in  several  vol- 
umes and  hence  impractical  for  text-book  purposes. 

No  attempt  has  been  made  to  outline  the  exact  method 
for  the  teaching  of  the  subjects,  as  this  must  vary  with  con- 
ditions. It  is  desirable  that  classwork  upon  the  text  should 
be  supplemented  by  laboratory  work.  The  nature  of  the 
laboratory  work  will  depend  upon  the  equipment  available. 
It  is  suggested  that  the  equipments  on  the  nearby  farms 
may  be  used  to  good  advantage.  Sample  machines  to  be 
used  for  study  may  be  secured  by  co-operation  with  dealers 
in  farm  machinery. 

The  author  will  be  very  glad  to  receive  criticisms  and 
suggestions  from  those  using  this  text,  in  regard  to  how  it 
may  be  improved  and  made  more  useful.  The  correction 
of  any  errors  will  likewise  be  appreciated. 


8  PREFACE 

Although  written  primarily  for  use  as  a  text  book,  it  is 
hoped  that  this  volume  will  be  of  interest  to  those  engaged 
in  practical  agriculture. 

Many  of  the  illustrations  were  made  from  photographs 
secured  from  the  files  of  the  Iowa  State  College.  In  addi- 
tion, the  trade  Uterature  of  the  following  manufacturers 
was  drawn  upon : 

International  Harvester  Company  of  America;  John 
Deere  Plow  Co.  of  Moline,  111.;  MoHne  Plow  Co.;  W.  &  L. 
E.  Gurley;  Eugene  Dietzen  Co.;  Keuffel  and  Esser  Co.; 
Parlin  and  Orendorff  Co. ;  Fairbanks,  Morse  and  Co. ;  Hayes 
Pump  and  Planter  Co. ;  Hunt,  Helm,  Ferris  &  Co. ;  J.  D.  Tower 
and  Sons  Co.;  Western  Wheeled  Scraper  Co.;  Pattee  Plow 
Co.;  Avery  Company;  Emerson-Brantingham  Co.;  M. 
Rumely  Co. ;  American  Seeding  Machine  Co. ;  Oliver  Chilled 
Plow  Works;  Hart-Parr  Co.;  Red  Jacket  Mfg.  Co.;  A.  Y. 
McDonald  Mfg.  Co.;  Louden  Machinery  Co.;  Gale  Mfg.  Co.; 
Sandwich  Mfg.  Co.;  Aspenwall  Mfg.  Co.;  Wilder-Strong 
Implement  Co. ;  Port  Huron  Engine  and  Thresher  Co. ;  J.  L. 
Owens  Co.;  Charles  A.  Stickney  Co.;  Twin  City  Separator 
Co.;  Cushman  Motor  Works;  F.  E.  Meyers  &  Bro.;  D.  M. 
Sechler  Carriage  and  Implement  Co.;  Roderick  Lean  Mfg. 
Co. ;  Janesville  Machine  Co. ;  LaCrosse  Plow  Co. ;  The  John 
Lanson  Mfg.  Co.;  J.  I.  Case  Plow  Works;  J.  I.  Case  Thresh- 
ing Machine  Co. ;  Johnson  &  Field  Mfg.  Co. ;  Racine  Sattley 
Co. ;  Kewanee  Water  Supply  Co. ;  and  others. 

Valuable  assistance  was  secured  from  Mr.  M.  F.  P. 
Costelloe,  Associate  Professor  of  Agricultural  Engineering, 
Iowa  State  College,  who  read  the  manuscript  for  Parts  I  to 
IV,  inclusive.  Mr.  J.  H.  Weir,  the  Editor,  did  very  efficient 
work  on  the  manuscript,  which  is  appreciated. 

Ames,  Iowa.  J.  B.  Davidson. 

February,  1913. 


CONTENTS 


Chapter 


Introduction 


Page 
13 


PART  I— AGRICULTURAL  SURVEYING 

I.     Definitions  and  Uses  of  Surveying     ...  16 
II.     Measuring — The  Use,  Care,  and  Adjustment  of 

THE  Instruments 18 

III.  Field  Methods  24 

IV.  Map  Making  28 

V.    Computing  Areas 34 

VI.    The  United  States  Public  Land  Survey     .       .  38 

VII.    Instruments  for  Leveling;  Definitions  .       .  42 

VIII.    Leveling  Practice 49 


PART  n— DRAINAGE 

IX.  Principles  of  Farm  Drainage 

X.  The  Preliminary  Survey    . 

XI.  Laying  Out  the  Drainage  System 

XII.  Leveling  and  Grading  Tile  Drains 

XIII.  Capacity  of  Tile  Drains 

XIV.  Land  Drainage 

XV.  Construction  of  Tile  Drains 

XVI.  Open  Ditches 

XVII.  Drainage  Districts 


56 
64 
67 
73 

78 

86 

96 

103 

108 


PART  in— IRRIGATION 

XVIII.    History,  Extent,  AND  Purpose  OF  Irrigation  .       .  Ill 

XIX.     Irrigation  Culture      ' 115 

XX.    Supplying  Water  for  Irrigation    ....  122 
XXI.    Applying  Water  for  Irrigation          .       .       .  129 
XXII.    Irrigation  in  Humid  Regions  and  Sewage  Dis- 
posal        136 


10 


CONTENTS 


Chapter 

XXIII. 

XXIV. 

XXV. 

XXVI. 

XXVII. 

XXVIII. 


XXIX. 

XXX. 

XXXI. 

XXXII. 

XXXIII. 

XXXIV. 

XXXV. 

XXXVI. 

XXXVII. 

XXXVIII. 

XXXIX. 

XL. 

XLI. 

XLII. 

XLIII. 

XLIV. 

XLV. 

XLVI. 

XLVII. 


PART  IV— ROADS 

Page 

Importance  of  Roads 141 

Earth  Roads           147 

Sand-Clay  and  Gravel  Roads      ....  153 

Stone  Roads    .       .       .       .       .       .       .       .       .  160 

Road  Machinery 167 

Culverts  and  Bridges 175 

PART  V— FARM  MACHINERY 

The  Relation  of  Farm  Machinery  to  Agricul- 
ture      180 

Definitions  and  Principles              ....  186 

Materials 195 

The  Plow 199 

Harrows,  Pulverizers,  and  Rollers         .       .  211 

Seeders  and  Drills 223 

Corn  Planters 231 

Cultivators 237 

The  Grain  Binder  or  Harvester       .       .       .  244 

Corn  Harvesting  Machines 251 

Hay-Making  Machinery 258 

Machinery  for  Cutting  Ensilage  ....  273 

Threshing  Machines 278 

Fanning  Mills  and  Grain  Graders       .       .       .  282 

Portable  Farm  Elevators 287 

Manure  Spreaders 292 

Feed  Mills  and  Corn  Shellbrs          .       .       .  298 

Spraying  Machinery 303 

The  Care  and  Repair  of  Farm  Machinery     .  309 


PART  VI— FARM  MOTORS 

XLVIII.  Elementary  Principles  and  Definitions      .       .  313 

XLIX.  Measurement  of  Power 316 

L.  Transmission  of  Power      ......  320 

LI.  The  Horse  as  a  Motor 327 

LII.  Eveners 334 

LIII.  Windmills 339 

LIV.  The  Principles^  of  the  Gasoline  Engine     .       .  344 


CONTENTS 


11 


Chapter  Page 

LV.    Engine  Operation .       350 

LVI.  Gasoline  and  Oil  Engine  Operation     .       .       .  354 

LVII.  Selecting  a  Gasoline  or  Oil  Engine        .       .       361 

LVIII.    The  Gas  Tractor 370 

LIX.    The  Steam  Boiler 376 

LX.    The  Steam  Engine 385 

LXI.    The  Steam  Tractor 389 

PART  Vn— FARM  STRUCTURES 

LXII,  Introduction  and  Location  OF  Farm  Buildings    .     395 

LXIII.     Mechanics  of  Materials 402 

LXIV.  Mechanics  of   Materials  and   Materials   of 

Construction 406 

LXV.    Hog  Houses 414 

LXVI.    Poultry  Houses 425 

LXVTI.     Dairy  Barns 436 

LXVIII.    Horse  Barns 442 

LXIX.     Barn  Framing 445 

LXX.    The  Farmhouse 451 

LXXI.  Constructing  the  Farmhouse       ....       455 

LXXII.    The  Silo 461 

LXXIII.  The  Implement  House  and  Shop        .       .       .       473 

PART  Vm— FARM  SANITATION 

LXXIV.    The  Farm  Water  Supply 480 

LXXV.    The  Pumping  Plant 486 

LXXVI.  Distributing  and  Storing  Water    ....  491 

LXX VII.  Plumbing  for  the  Country  House                    .       497 

LXXVIII.  The  Septic  Tank  FOR  Disposal  OF  Farm  Sewage     .    501 

LXXIX.  The  Natural  Lighting  of  Farm  Buildings     ,       506 

LXXX.     Lighting  the  Country  Home 510 

LXXXI.  The  Acetylene  Lighting  Plant  ....       515 

LXXXII.    The  Electric  Lighting  Plant 520 

LXXXIII.  Heating  the  Country  Home         ....       525 

LXXXI V.  Ventilation  of  Farm  Buildings      .       .       .       .531 

PART  IX— ROPE  WORK 
LXXXV.    Ropes,  Knots,  and  Splices 537 


Agricultural  Engineering 


INTRODUCTION 

Engineering.  Defined  briefly,  engineering  is  the  art  of 
directing  the  forces  of  nature  to  do  economically  the  work 
of  man.  The  pursuit  of  agriculture  requires  many  mechani- 
cal operations  which  involve  the  use  of  engineering  methods. 

Consider  the  production  of  wheat.  The  plowing,  the 
pulverizing  and  smoothing  of  the  soil,  the  cleaning  and  grad- 
ing of  the  seed,  the  drilling  of  the  seed,  the  harvesting,  the 
thrashing,  and  the  hauling  of  the  crop  to  market,  are  all 
mechanical  operations  to  which  the  skill  of  the  mechanic  or 
engineer  should  be  applied  in  order  to  obtain  the  best  results. 

In  like  manner,  if  the  production  of  other  crops  be  con- 
sidered, it  will  be  found  that  there  are  many  operations  to  be 
performed  in  connection  therewith,  which  will  require  the 
directing  of  the  forces  of  nature  or  the  application  of  engineer- 
ing principles. 

Agricultural  Engineering.  In  the  broadest  sense,  agri- 
cultural engineering  is  intended  to  include  all  phases  and 
branches  of  engineering  directly  connected  with  the  great 
industry  of  agriculture.  In  America  it  is  only  recently  that 
the  term  agricultural  engineering  has  come  into  general  use. 
The  term  rural  engineering  is  used  by  some  to  designate  the 
same  subject. 

It  is  only  within  the  last  few  years  that  the  importance  of 
agricultural  engineering  as  a  branch  of  agricultural  education 
has  been  recognized.     A  knowledge  of  soils  and  of  the  plants 

13 


14       •  Y*  t*'i?"AQ^t^VJUTVRJ^L  ENGINEERING 

and  animals  of  the  farm  is  essential  to  those  who  would  make 
good  farming  the  aim  of  their  Ufe's  work,  and  these  subjects 
should  be  carefully  studied  by  the  agricultural  student. 
But  the  study  of  agricultural  engineering  is  quite  as  impor- 
tant in  assuring  that  efficiency  in  farm  management  which 
results  in  the  greatest  and  most  permanent  benefits. 

The  truth  of  the  foregoing  statement  is  better  understood 
when  one  learns  that  the  producing  capacity  or  earning  ability 
of  the  farm  worker  is  in  direct  proportion  to  the  amount  of 
power  one  is  able  to  control.  There  was  a  time  when  man 
tilled  the  soil  by  his  own  individual  efforts,  depending  upon 
no  other  source  of  power  than  the  strength  of  his  own  body. 
Later,  one  beast  per  worker  was  pressed  into  service  to  draw 
suitable  implements.  Still  later,  two  animals  were  used,  and 
development  has  continued,  until  at  the  present  time  we  have 
reached  the  "age  of  four-horse  farming.'*  In  other  words, 
the  four-horse  team  is  now  recognized  as  the  most  efficient 
one  for  field  work. 

Man  as  a  motor  or  producer  of  power  is  able  to  develop 
about  one-eighth  of  one  horsepower.  When  use  was  made 
of  one  good  horse  per  worker,  man's  labor  capacity  was 
increased  eightfold.  When  four  horses  became  the  unit, 
his  efficiency  was  multiplied  about  32  times.  Just  now  there 
is  a  desire  to  increase  still  further  the  amount  of  power  for 
each  farm  worker,  by  the  use  of  powerful  tractors  or  engines 
arranged  for  drawing  and  operating  farm  implements. 

The  application  of  power  to  farm  operations,  which  must 
come  mainly  through  the  use  of  machinery,  is  only  one  branch 
of  agricultural  engineering.  Some  element  of  agricultural 
engineering  is  concerned  in  nearly  every  department  of 
agricultural  endeavor.  It  serves  man  in  one  or  both  of 
two  ways :  ( 1 )  By  making  it  possible  to  increase  the  capacity 
of  the  worker,  as  just  explained;  and  (2)  by  making  condi- 


INTRODUCTION  IB 

tions  more  desirable  and  satisfactory,  either  by  relieving  the 
worker  of  hard  labor,  or  by  providing  more  healthful  and 
pleasing  surroundings. 

Farm  Mechanics.  The  term  Farm  Mechanics  is  not  as 
comprehensive  in  meaning  as  Agricultural  Engineering,  yet 
it  is  often  used  to  designate  the  same  branch  of  education. 
Mechanics  is  the  science  of  forces  and  their  actions;  whereas 
engineering  proper  is  based  upon  a  knowledge  of  these  forces 
and  treats  more  particularly  of  the  directing  of  them  to 
secure  their  most  advantageous  use. 

In  this  text  the  subject  of  agricultural  engineering  is 
presented  under  the  following  heads : 

Agricultural  Surveying. 

Drainage. 

Irrigation. 

Roads. 

Farm  Machinery. 

Farm  Motors. 

Farm  Structures. 

Farm  Sanitation. 
The  importance  and  relation  of  these  various  branches 
to  agriculture  are  discussed  in  the  separate  parts  of  the  text 
devoted  to  each. 

QUESTIONS 

1.  Define  the  term  engineering. 

2.  Show  how  engineering  methods  are  involved  in  crop  production. 

3.  Define  the  term  agricultural  engineering. 

4.  Is  there  any  relation  between  the  producing  capacity  of  a  farm 
worker  and  the  amount  and  kind  of  power  used? 

5.  Distinguish  between  "farm  mechanics"  and  'agricultural 
engineering." 

6.  Name  the  principal  branches  of  agricultural  engineering. 


PART  ONE— SURVEYING 


CHAPTER  I 
AGRICULTURAL  SURVEYING 

Surveying.  The  object  of  agricultural,  or  land,  survey- 
ing, in  its  generally  accepted  meaning,  is  to  determine  and 
place  on  record  the  position,  area,  and  shape  of  a  tract  of 
land.  The  various  steps  taken  to  accomplish  this  end  con- 
stitute a  survey.  In  addition  to  the  field  work  with  instru- 
ments for  measuring  distances,  angles,  and  directions,  a 
field  record,  containing  figures,  notes,  and  sketches  concern- 
ing the  work  must  be  kept;  the  areas  must  be  computed;  and 
usually  a  map,  plat,  or  profile  made  showing  the  tract  of  land 
surveyed.  The  art  of  land  surveying  includes  all  of  these 
various  lines  of  work. 

Uses  of  Surveying.  Agricultural  students  can  well 
afford  to  spend  some  time  in  the  study  of  land  or  agricultural 
surveying.  The  object  of  the  work  here  presented  on  sur- 
veying is  to  enable  the  student  to  measure  and  calculate 
accurately  the  areas  of  the  various  fields  of  the  farm  and 
to  locate  the  buildings;  to  prepare  a  good  map  setting 
forth  the  relative  size  and  position  of  the  fields,  buildings, 
and  fences,  and  indicating  the  drains;  and  to  prepare  the 
student  for  the  study  of  drainage  and  irrigation. 

It  is  necessary  for  the  farmer  to  know  the  areas  of  his 
fields  in  order  that  he  may  determine  accurately  the  yields 
of  the  various  crops  grown.  A  survey  will  enable  the  farmer 
to  so  divide  his  farm  into  fields  as  to  facilitate  a  system  of 
crop  rotation. 

16 


SURVEYING  17 

A  good  map  is  a  means  of  recording  the  location  of  drains 
and  water  pipes  laid  beneath  the  surface  of  the  ground.  It 
will  also  enable  the  farmer  to  direct  the  work  of  the  farm 
more  easily,  and  to  make  a  study  of  the  most  convenient 
arrangement  of  fields  and  buildings.  This  method  is  used 
by  architects  and  engineers  in  planning  buildings  and 
engineering  work  such  as  factories  and  railroads. 

Divisions  of  Agricultural  Survejdng.  The  work  of  mak- 
ing a  survey  resolves  itself  into  three  stages  or  operations, 
as  follows : 

1.  Measuring  and  recording  distances  and  angles,  involv- 
ing the  use,  care,  and  adjustment  of  the  instruments  used  in 
the  survey. 

2.  Drawing  the  tract  surveyed  to  a  suitable  scale,  or 
proportion. 

3.  Calculating  the  areas  of  the  tracts  surveyed. 

QUESTIONS 

1.  What  is  the  object  of  agricultural  surveying? 

2.  Define  a  survey. 

3.  To  what  use  can  a  knowledge  of  surveying  be  put  by  those  con- 
nected with  agriculture? 

4.  In  what  way  will  a  map  be  of  use  to  the  land-owner? 

5.  Describe  the  three  divisions  of  agricultural  surveying. 


CHAPTER  II 
MEASURING;     USE  AND  CARE  OF  INSTRUMENTS 

Instruments  for  Measuring  Distances.  Often  students 
are  led  to  think  that  it  is  impossible  to  make  a  survey  without 
a  very  elaborate  equipment  of  expensive  instruments,  but 
this  is  not  true.  An  agricultural  survey,  such  as  is  usually 
required  by  the  farm  owner  or  manager,  can  be  accomplished 
with  simple  and  quite  inexpensive  instruments.  Where  the 
boundary  of  the  tract  of  land  is  known,  a  practical  survey 
may  be  made  with  a  surveyor's  chain  or  tape. 

Gunter's  Chain.  Much  of  the  land  in  the  United  States 
was  surveyed  originally  with  the  Gunter's  chain,  which  is 
now  but  Uttle  used.  This  chain  is  66  feet 
long,  divided  into  100  links,  each  of  which, 
including  the  connecting  rings  at  the  ends, 
is  7.92  inches  long.  The  Unks  are  made  of 
steel  or  iron  wire,  and  the  better  chains 
have  the  open  joints  soldered  or  brazed  to- 
gether. The  reason  for  making  the  Gunter's 
chain  of  the  length  of  66  feet  or  100  Hnks  is 

owing  to  its  convenient  relation  to  the  stand- 
Fig.     1.     The  ° 

Gunter's  chain,  ard  uuits  of  length  and  area  in  use.  The 
chain  is  1-80  of  a  mile,  or  four  rods.  A 
square  chain  is  1-10  of  an  acre.  Thus  ten  square  chains 
make  an  acre,  and  this,  together  with  the  fact  that  links 
may  be  written  as  a  decimal  of  a  chain,  greatly  facilitates 
computations.  To  illustrate,  1625  square  chains  equal  162.5 
acres,  and  15  chains  and  24  links  equal  15.24  chains. 

18 


SURVEYING  19 

The  Gunter's  chain  has  been  used  on  all  United  States 
land  surveys;  and  in  deeds  of  conveyance  and  other  legal 
documents,  when  the  word  chain  is  used,  the  Gunter's 
chain  of  66  feet  is  mean^o 

Table  of  Linear  Measure. 

12  inches  (in.  or  ")  make  1  foot  (ft.  or   ) 

3      feet  .    *'     1  yard  (yd.) 

5}4  yards  or  163^  feet      "     1  rod     (rd.) 
320      rods  "     1  mile  (mi.)  . 

Equivalent  Table 

Mi.               Rd.             Yd.                Ft.  In. 

1             320         1760            5280  63360 

1               53^            16^  198 

1                 3  36 

1  12 
Table  of  Gunter*s  Chain  Measure. 

7.92    inches  (in.  or  ")  make  1  link     (li.) 

100  links  "    1  chain  (ch.) 

80  chains  "    1  mile    (mi.) 

Equivalent  Table 
Mi.  Ch.  Li.  In. 

1  80  8000  63360 

1  100  792 

1  7.92 

Table  of  Surface  Measure. 

144     square  inches  (sq.  in.)  make  1  square  foot   (sq.  ft.) 

9         "        feet  "    1        "  yard  (sq.  yd.) 

30M     "       yards  "   1        "  rod     (sq.  rd.) 

160         "       rods  "    1  acre 


Equivalent 

Table 

A. 

Sq.  rd. 

Sq.  yd. 

Sq.  ft. 

Sq.  in. 

1 

160 

4840 

43560 

6272640 

1 

30^ 

272M 

39204 

1 

9 
1 

1296 
144 

20 


AGRICULTURAL  ENGINEERING 


Surveyor's  Measure. 

625  square  links 
16     "      rods 
10     "      chains 

(sq.  li.)  make  1  square 
''      1      "       ( 
"     1  acre 

rod  (sq.  rd.) 
ihain  (sq.  ch.) 

640  acres 

''      1  square 
Equivalent  Table 

mile, 

or  one  section 

A. 
1 

Sq.  ch.                   Sq.  rd. 

10                  160 

1                    16 

1 

Sq.  li. 

100,000 

10,000 

625 

Cloth  and  Metallic  Tapes.  Tapes  made  of  linen  cloth 
are  not  practical  to  use  in  land  surveying,  even  when  well 
made  and  water-proofed.  They  will  stretch  when  pulled  up 
tight,  and  are  difficult  to  handle  in  the  wind.  A  cloth 
tape  is  much  improved  when  small  brass  wires  are  woven 
lengthwise  into  it  to  check  the  tendency  to  stretch.  Such 
a  tape  is  said  to  be  a  metallic  tape.  These  tapes  are  made  to 
wind  into  a  case  of  sheet  metal  or  leather,  and  for  this  reason 
are  very  convenient  to  carry  about. 
Steel  Tapes.  The  steel  tape  is 
now  the  standard  measuring  in- 
strument, as  it  has  many  advan- 
tages. It  does  not  kink,  stretch,  or 
wear  so  as  to  change  its  length. 
The  steel  tape  may  be  obtained  in 
lengths  varying  from  3  feet  to  1000 
feet.  These  tapes  may  be  marked 
or  graduated  in  any  form  desired. 
The  two  common  methods  of 
marking  the  tape  are  by  either 
etching  the  surface  with  acid,  or  stamping  the  marks  on 
solder  placed  on  the  tape  at  the  desired  places.    A  tape 


Fig-.  2.  A  motallic  tape. 
This  tape  has  brass  or  cop- 
per wires  woven  into  it 
lengthwise. 


SURVEYING 


21 


Fig.   3.     A  steel   tape  wound  on  a  reel. 


mm. 


100  feet  long  is  usually  termed   the  engineer's  tape,    and 
either  this  length  or  the  50  foot  tape  is  the  most  convenient. 

The  average  width  of 
the  steel  tape  is  5-16  of 
an  inch,  and  the  thick- 
ness about  .02  of  an  inch. 
Short  tapes  are  arranged 
to  be  carried  in  metal  or 
leather  cases,  but  longer 
tapes  are  carried  either 
on  reels  or  are  "  thrown '^ 
into  a  coil  from  which  they  can  be  unwound  without  danger 
of  kinking. 

Arrows,  or  Marking  Pins.  For  mark- 
ing points  temporarily  while  measuring  with 
a  tape  or  chain,  arrows,  or  marking  pins, 
are  used.  These  are  made  of  stout  wire, 
pointed  at  one  end,  with  a  large  eye  or  ring 
at  the  other.  In  order  that  the  pins  may 
be  easily  found  in  the  grass  or  leaves,  a 
piece  of  colored  cloth  should  be  tied  to  the 
rings.  Eleven  pins  are  required  for  a  com- 
plete set,  and  are  best  carried  on  a  ring 
with  9i  spring  catch. 

Range  Poles  or  Flagstaffs  are  used  to 
locate  points  in  establishing  a  line.  They  are  rods  or  poles 
usually  6  to  10  feet  long,  made  of  wood  or  iron,  pointed 
so  as  to  be  easily  planted  in  the  ground,  and  painted  red 
and  white  alternately  in  foot  sections. 

Flagstaffs  should  be  placed  directly  over  the  points  they 
are  to  mark,  and  great  care  should  be  used  to  plant  them  truly 
vertical.  Much  skill  may  be  attained  by  practice  in  estab- 
lishing lines  with  flagstaffs,  and  this  skill  will  be  found  very 
useful  in  laying  out  fields,  fences,  etc. 


Fig.      4.      Arrows 
or  pins. 


22  AGRICULTURAL  ENGINEERING 

The  Care  and  Use  of  Chains  and  Tapes.  The  chain  is 
folded  by  starting  at  the  middle  and  folding  in  the  two  halves 
at  the  same  time.  It  is  opened  by  holding  the  two  handles 
in  one  hand  and  throwing  out  the  chain  with  the  other. 
The  steel  tape  is  wound  on  a  reel  or  thrown  into  a  coil,  the  lat- 
ter method  requiring  some  practice  and  skill  to  prevent  kinks. 
Chains  and  tapes  are  used  in  measuring 
horizontal  distances;  and  for  this  purpose  they 
should  be  held  horizontal,  or  level,  when  meas- 
uring, not  parallel  to  the  surface  of  the  ground. 
The  chain  or  tape  should  be  pulled  taut  enough 
to  overcome  the  shortening  due  to  the  sag. 
Where  distances  are  to  be  obtained  with  great 
accuracy,  the  chain  or  tape  should  be  tested 
often  over  a  known  fixed  distance  to  determine 
the  amount  of  pull   necessary  to  bring  it  to 

I  the  true  length.     Chains  in  constant  use  re- 

quire frequent  adjustment  for  wear. 
Each  pin  should  be  so  placed  that  its  thick- 
ness will  not  be  added  to  the  length  of  the  chain. 
Care  should  be  taken  to  set  the  pins  vertical. 
When  chaining  up  or  down  slopes,  one  end  of  the 
chain  must  be  held  high  to  make  it  level,  when  it 
becomes  necessary  to  transfer  a  point  from  the 
elevated  end  vertically  to  the  ground.  This  can 
p.  best  be  done  with  a  plumb-bob  and  string,  and 

A   wooden       whcu  this  is  uot  at  hand  a  pin  may  be  dropped 

range  pole.  ^  ^  *'  ^^ 

from  the  elevated  end  of  the  chain  or  tape  and 
the  point  where  it  strikes  the  ground  noted. 

In  chaining  practice,  the  man  leading  is  called  the  head 
chainman,  and  the  other  the  rear  chainman.  In  beginning 
a  measurement,  the  rear  chainman  marks  the  starting  point 
with  one  of  the  eleven  pins  in  the  set,  and  gives  the  remain- 


SURVEYING  23 

ing  ten  to  the  head  chainman,  who  counts  them.  The  head 
chainman  then  leads  away  with  the  chain  or  tape  toward  the 
point  to  which  the  distance  is  to  be  measured.  When  the 
rear  end  of  the  extended  tape  is  near  the  starting  point,  the 
rear  chainman  calls  "chain"  or  "tape,"  as  signal  for  the  head 
chainman  not  to  go  too  far.  The  chain  is  then  stretched  full 
length,  and  the  rear  chainman  lines  the  front  chainman  with 
the  objective  point  by  motioning  with  his  head  or  other- 
wise indicating  the  direction  he  should  move.  When  the 
head  chainman  has  the  chain  in  Hne,  the  rear  chainman  calls 
"stick,"  indicating  that  he  has  the  chain  to  the  pin.  The 
head  chainman  then  pulls  the  chain  tight,  and  sets  a  pin, 
caUing  "stuck."  The  rear  chainman  pulls  the  rear  pin, 
and  both  men  move  ahead  and  repeat  the  operation  from 
the  second  pin;  and  so  on.  When  the  head  chainman  has 
placed  his  ten  pins,  he  calls  "tally,"  and  waits  for  the  rear 
chainman  to  walk  forward  to  him  and  give  him  the  ten  pins 
he  has  collected. 

Pacing.  The  ability  to  estimate  distances  accurately  by 
pacing  is  often  useful.  Skill  may  be  developed  by  pacing 
known  distances  until  the  length  of  the  individual  pace  is 
determined  and  can  be  regulated. 

QUESTIONS 

1.  What  instruments  are  needed  in  making  a  practical  survey  of  a 
tract  of  land  where  the  boundaries  are  known? 

2.  Describe  the  Gunter's  chain. 

3.  Recite  the  four  tables  used  in  measuring  surfaces. 

4.  Describe  the  differences  in  tapes. 

5.  Describe  the  use  of  range  poles.     Of  marking  pins. 

6.  How  is  the  chain  cared  for?    The  steel  tape? 

7.  Describe  the  process  of  chaining. 

8.  In  what  way  will  the  ability  to  estimate  distances  by  pacing 
be  useful? 


CHAPTER  III 


FIELD  METHODS 

Making  Chain  Surveys.  For  many  practical  purposes  a 
survey  made  with  the  tape  or  chain  alone  will  be  quite 
satisfactory.  To  make  such  a  survey  for  area,  the  land 
is  divided  into  rectangles  or  triangles,  or  both.  The  areas 
of  any  of  these  may  be  easily  calculated  when  the  length  of 
each  side  is  known. 

Making  Notes.     In  all  surveys,  all  figures,  notes,  and 

sketches  should  be  sys- 


SURVEY   OF    HELD 


AB 

BC 

CO 

DE 

EA 

BE 

BD 


14  0 
150 
200 
£50 
ISO 

no 

155 


ABCO    WITH  TAPE 


Head  chointnai)  R.Roe 
Rear chainman  I. Doe 

Sept  I  1911  -  3  hrs. 
Cloudy    and  cool 

Used  steel  tope  looft. 

Measured  each  side 

in  turn   once 


tematically  recorded  in  a 
suitable  book,  and  these 
go  to  make  what  is  called 
jield  notes.  From  these 
notes  the  map  is  later 
made  and  the  areas  cal- 
culated. 

The  most  simple 
method  of  making  field 
notes  is  to  make  a  free- 
hand sketch  of  the  field 
as  nearly  correct  as  the 
eye  can  determine.  All 
corners  should  be  designated  by  letters  and  the  same 
marked  on  the  sketch,  which  is  used  as  a  guide.  All 
distances  between  corners  should  be  recorded,  not  only 
in  the  sketch,  but  also  in  suitable  columns.  The  points 
where  fences,  streams,  and  roads  are  crossed  in  measurement 
should  be  noted  on  the  sketch.  If  the  tract  surveyed  is  so 
large  that  the  sketch  is  likely  to  become  confused,  the  entire 

24 


Fig.   6.     A  form  for  field  notes. 


SURVEYING 


25 


tract  may  be  sketched  on  one  page,  and  details  of  certain 
parts  on  other  pages. 

All  field  notes  should  be  carefully  recorded  in  a  well- 
bound,  durable,  and  convenient  field  book.  The  standard 
field  book  has  pages  about  4  by  7  inches,  ruled  in  any  one  of 
the  several  forms  of  ruling,  and  is  substantially  bound. 
The  notes  should  be  neatly  made  with  a  hard  pencil  in  order 
that  they  will  not  blur  with  use.  In  the  sketches,  the  cus- 
tomary symbols  employed  in  map  making  may  be  used. 
These  will  be  described  later. 

Field  Methods.  In  making  a  chain  survey,  it  is  to  be 
remembered  that,  since  angles  are  not  measured,  more  meas- 
urements will  be  required.  Many  fields  are  rectangular, 
and  their  measurement  is  correspondingly  simple.  When 
the  angles  are  not  right  angles  they  may  be  determined  by 
measuring  three  sides  of  a  triangle  laid  off  in  the  corner, 
making  two  sides  or  the  legs  of  the  triangle  coincide  with  the 
sides  of  the  field. 

Marking  Points  in  a  Survey.    In  making  a  survey  all  the 
important  points  should  be  marked  for  future  reference.     In 
laying  out  fields  and  lots,  some  permanent  mark   should 
be  set  at  the  corners.     If  a  corner 
post  is    not    used,    a    stone  or    a 
block  of   concrete  should  be  set  in 
the  ground  and  a  cross  chiseled  on 
the  surface  to  indicate  clearly   the 
point.    Stakes  of  durable  wood  may 
be  used  to  good   advantage.     The 
exact  point  may  be  indicated  by  driv- 
ing a  tack  in  the  top  of  the  stake.    A 
stake  two   inches   square    is  often 
used.    The  field  notes  describing  the 


Fig. 
how   a 


7.      Sketch     showing: 
line   may  be   laid  off 


location  of  these  points  should  be   l\  iToLrf  '°  ^'"'''^"' 


26  AGRICULTURAL  ENGINEERING 

complete  and  clear  enough  to  make  it  easy  for  anyone  to  find 
the  corners  again  at  some  future  time. 

PROBLEMS  FOR  PRACTICE 

(In  order  to  carry  out  the  following  problems  it  will  be  necessary 
to  be  provided  with  equipment  consisting  of  tapes,  pins,  and  range 
poles.) 

1.  With  chain  and  range  poles  lay  off  a  right  angle. 

Note.  3,  4,  and  5  feet,  or  corresponding  multiples  of  these  dis- 
tances, are  sides  of  a  right  angle  triangle.  Give  the  theorem  of  geometry 
upon  which  this  is  based.     (Fig.  7). 

2.  Measure  the  distance  between  two  points  a  thousand  feet  or 
more  apart  and  check  with  the  results  obtained  by  the  instructor. 


Rando^n   L/ne^ 


True  L/ne 

Fig.  8.     Sketch  showing'  method  of  locating  points  on  a  desired  line 
between  two  points  not  visible  from  each  other  from  a  random  line. 

3.  Let  each  student  pace  this  or  some  other  known  distance  and 
determine  the  length  of  his  pace. 

4.  Estimate  certain  distances  by  pacing,  and  then  measure  accu- 
rately with  a  steel  tape. 

5.  Chain  over  a  hill  between  two  points  not  visible  from  each 
other. 

Range  poles  should  be  set  at  the  points  and  then  the  chainmeri 
with  range  poles  should  take  such  positions  on  each  side  of  the  hill  as 
will  enable  each  to  see  over  the  hill  and  past  the  other  chainman  to 
the  range  pole  beyond.  The  chainmen  then  range  each  other  in.  mak- 
ing several  trials. 

6.  Chain  between  two  points  when  the  view  is  obstructed  by  woods 
or  other  objects. 

To  accomplish  this,  run  a  trial  or  random  straight  line  as  near  as 
possible  to  the  distant  point,  leaving  fixed  points  at  known  distances. 
Upon  finding  the  error  at  the  terminus,  correct  all  other  points  into 
line  a  proportionate  amount.    Then  the  desired  line  may  be  chained. 


SURVEYING 


27 


7.  Determine  the  distance  to  a  visible  but  inaccessible  object. 
Use  two  similar  right-angled  triangles.     Fig.  9. 

8.  Prolong  a  line  beyond  an  obstacle. 

There  are  several  ways  to  accomplish  this,  but  the  use  of  similar 
triangles  is  the  only  method  suggested. 

Let  A  B  be  points  in  the  Hne  to  be  prolonged  beyond  O,  an  obstacle. 
Make  A  B  C  a  right-angled  triangle.  Prolong  A  C  to  F,  making  C  F 
equal  A  C,  and  C  E  equal  E  F,  and  B  C  equal  C  D.  Extend  D  E  to  I, 
making  DG  and  G  I  equal  to  A  C,.also 
extend  F  G  to  H,  making  G  H  equal  F  G. 
Then  H  I  are  points  in  the  extended  line 
AB. 


Fig.  9.  Sketch  showing 
method  of  measuring  to  an 
inaccessible  point. 


Fig.   10.     Sketch  showing   method  of  extend- 
ing   a    line    beyond    an  "obstacle. 


9.  Make  a  survey  of  the  lot  on  which  the  schoolhouse  stands, 
locating  buildings,  etc. 

10.  Make  a  survey  of  the  home  farm  or  a  part  of  it,  as  assigned  by 
the  instructor. 

11.  Make  a  survey  of  a  lot  or  a  field  having  an  irregular  side,  by 
taking  oflFsets  at  regular  or  irregular  intervals,  dividing  the  field  into 
trapezoids.     (See  method  of  calculating  areas  of  tracts  with  irregular 


QUESTIONS 

1.  How  is  a  tract  of  land  divided  in  making  a  chain  survey? 

2.  What  care  should  be  taken  in  making  field  notes  of  a  survey? 

3.  What  care  should  be  taken  in  marking  permanent  comers? 


CHAPTER  IV 
MAP  MAKING 

Uses  of  a  Map.  When  a  survey  of  a  farm  or  other  tract 
of  land  has  been  made,  a  map  should  be  drawn  to  show  the 
location  of  the  buildings,  fences,  lots,  roads,  and  of  the  trees, 
streams,  and  other  physical  features  of  the  land.  A  map 
enables  the  mind  to  grasp  the  facts  in  a  way  not  possible 
with  the  field  notes  alone.  Although  not  generally  practiced, 
a  good  map  of  the  farm  can  be  used  advantageously  in 
directing  the  work  of  the  farm.  This  map  should  also  serve 
as  the  means  of  recording  the  location  of  drains  and  water 
pipes  placed  beneath  the  surface  of  the  ground.  If  the  fields 
are  numbered  and  the  map  placed  in  the  office  or  dining 
room  of  the  home,  it  may  be  used  as  a  basis  in  planning  each 
day's  work.  The  map  will  set  also  forth  in  a  very  forceful 
way  any  inconvenience  in  the  arrangement  of  the  buildings 
or  fields. 

The  Final  Map.  The  final  map  is  made  from  the  data 
recorded  in  the  field  book.  As  has  been  said,  a  sketch  map 
usually  forms  a  very  helpful  part  of  the  field  notes.  The 
final  map  must  be  drawn  carefully  as  well  as  accurately, 
and  should  be  made  as  durable  as  possible. 

Drawing  Instruments.  The  equipment  for  making  maps 
may  be  quite  extensive,  yet  the  essential  instruments  are  not 
many  in  number  nor  are  they  expensive.  A  good  outfit 
includes  the  following:  A  drawing  board  of  soft  wood  and 
about  20  by  30  inches  in  size,  a  T  square,  a  triangle,  a  scale 
providing  at  least  10  and  50  divisions  to  the  inch,  a  ruhng 
or  right-line  pen,  a  compass  for  drawing  circles,  a  bottle  of 


SURVEYING 


29 


India  ink,  and  a  pen,  a  pencil,  an  eraser,  thumb  tacks,  etc. 
A  bottle  of  carmine  ink  is  convenient  but  not  necessary. 
When  angles  are  to  be  plotted  a  protractor  is  quite  necessary. 
A  good  quality  of  drawing  paper  should  be  used,  or  one 
that  will  stand  reasonably  hard  usage  in  folding  and  handling. 
A  good  quality  of  paper  is  known  as  bond  paper,  and  a  con- 
venient size  of  sheet  is  18  by  24  inches.  A  drawing  made  on 
this  bond  paper  may  be  reproduced  by  blue  printing,  a 
process  similar  to  the  making  of  photograph  prints  from 


Flgr.  11.  A  set  of  drawing  instruments,  consisting  of  a  drawing 
board,  a  T  square,  a  triangular  scale,  two  triangles,  a  protractor, 
a  case  of  instruments,  an  irregular  curve,  paper,  inli,  tacks,  etc. 
This  F(t  is  more  complete  than  is  required  for  map  making  as  indi- 
cated In  text. 


negatives.  The  process  is  rapid,  requiring  but  a  few  min- 
utes, and  the  cost  of  the  blue-print  paper  is  but  a  few  cents  per 
yard.  A  better  print  can  be  obtained,  however,  from  a 
drawing  made  on  tracing  cloth,  which  is  thin  and  so  prepared 
as  to  make  it  practically  transparent.    Where  expensive 


30 


AGRICULTURAL  ENGINEERING 


maps  are  to  be  prepared,  one  of  the  heavy,  serviceable  papers, 
like  Whatman's  hot-pressed  paper,  is  desirable. 

Making  the  Map.  In  making  a  map,  the  proper  scale 
to  use,  that  is,  the  ratio  between  the  actual  distances  in  the 
surveyed  tract  and  corresponding  ones  for  the  map,  must 
first  be  decided  upon.  In  the  case  of  an  average-sized  farm, 
100  or  200  feet  to  the  inch  is  a  convenient  scale.  The  larger 
the  area  or  the  smaller  the  maps  the  greater  will  be  the  dis- 
tance represented  by  one  inch  on  the  map.  If  the  scale, 
(meaning  the  instrument  used  for  measuring)  be  graduated 
so  as  to  give  50  divisions  to  the  inch,  it  will  be  easy  to  use 

with  any  of  the  ratios  proposed. 
For  instance,  suppose  the  ratio  of 
100  feet  to  the  inch  be  adopted, 
then  one  division  on  the  scale  will 
represent  2  feet;  and  if  200  feet  be 
adopted  as  a  ratio,  then  one  divi- 
sion will  equal  4  feet,  etc. 

The  handling  of  the  drawing 
instruments  mentioned  is  simple. 
The  head  of  the  T  square,  when 
held  by  the  hand  against  the 
straight  edge  of  the  drawing  board, 
will  permit  the  drawing  of  parallel 
lines.  By  holding  the  triangle 
against  the  blade  of  the  T  square, 
all  vertical  lines  may  be  drawn  accurately.  The  ruHng  or 
right-line  pen  is  used  in  drawing  straight  lines  on  the  final 
map  with  the  India  ink. 

The  first  operation  to  perform  in  preparing  a  map  is  to 
lay  off  the  boundary  of  the  tract  to  be  mapped.  Then  the 
location  of  other  features  may  be  added.  Angles  may  be 
plotted  in  by  the  use  of  the  protractor,  if  angles  have  been 


Fig.  12.  I^aying  out  a  tii 
angle,  the  length  of  the  thre 
sides  being  given. 


SURVEYING 


31 


read.  The  use  of  instruments  for  measuring  angles  will  be 
described  later.  If  measurements  have  been  made  to 
determine  angles,  these  angles  may  be  laid  out  with  the  aid 
of  the  compass,  setting  this  instrument  with  the  scale  and 
describing  circles  whose  radius  is  equal  to  the  length  of  the 
sides  of  the  triangle.  The  map  should  first  be  made  with  a 
pencil,  and  then,  after  every  feature  has  been  drawn,  should 
be  inked  in. 

Common  Topographical  Signs.     A  topographical  map  is 
one  which  gives  the  general  character  of  the  land  surface, 


Mactxi.  Road 


Second  ry 
Private  or  Farm 


Hadqe. 
Wire  Fence. 
Rail  *••*    * 


Stream. 


Railways. 


0  000600 
000000 

000000 


Cultivated  Land.     Windbreak. 


Contour 


Contour 


C^ 

Q 

O 

Q 

c2t 

^' 

S> 

O 

Q 

Q 

Q> 

O 

<^ 

($ 

Q 

<0 

Lawn. 


^  *      a  o  G)  a®'^ 


Orchard.        DeciduousTreea.      Evergreens 


Fig.    13.     Conventional   topographical   signs. 

showing  where  there  are  roads,  buildings,  forests,  swamps, 
etc.  To  facihtate  the  making  of  such  maps,  it  is  customary 
to  use  certain  symbols  or  methods  of  representing  certain 
conditions  of  the  surface.  A  general  use  of  certain  symbols 
to  indicate  certain  things  has  resulted  in  their  being  known 


32  AORWULTURAL  ENGINEERING 

as  conventional  topographic  signs.  It  is  not  sufficient,  how- 
ever, that  these  conventional  signs  alone  be  used,  but  should 
be  supplemented  with  notes. 

Lettering.  Maps  made  by  professional  draftsmen  or 
engineers  have  all  notes  and  titles  neatly  lettered  in.  The 
ability  to  do  lettering  quickly  and  neatly  is  a  part  of  the  train- 
ing of  the  engineer.     Letters  for  titles  are  often  made  by  the 


a b  c  d et g h ijk Imno p  qrstu  V  VJ X y  z 
/^J456  7  8  90 
ABCDtrGHIJKLMNOPQRS  TU  V  WX  YZ 
Inclined  Leifering,  for  Descrfpiion- 

abcdefghljklmnopqr  s+uvw  xyz. 

ABCDEPGHUKLM  N0PQR5TUVWX  Y  Z 
1234567890 
Upright  Lettering, for  Captions. 


Fig-.   14.      Good  styles  of  free-hand  lettering. 

use  of  instruments,  but  on  most  maps  the  letters  must  be 
made  with  a  form  of  the  writing  pen,  the  only  instruments 
used  being  the  T  square  and  triangle  with  which  the  guide 
lines  are  drawn,  to  assist  in  making  the  letters  even  and  of 
uniform  height.  While  it  is  not  best  to  attempt  to  duplicate 
the  work  of  the  professional  engineer,  it  is  desirable  that  all 
maps  be  of  as  neat  appearance  as  practical;  and  few  things 
add  to  or  detract  from  the  appearance  of  a  map  quite  so  much 
as  lettering.  The  best  lettering  is  that  which  is  simple  and 
easily  and  quickly  made.  A  good  alphabet  is  furnished  in 
Fig.  14,  and  is  a  form  of  lettering  now  in  general  use.  The 
beginner  should  first  pencil  the  letters  on  the  map;  and  when 


SURVEYING 


33 


an  arrangement  of  the  notes  is  found  which  is  adapted  to  the 
map,  they  should  be  traced  with  drawing  ink.  Although 
not  absolutely  essential,  it  is  suggested  that  all  maps  be 
lettered  in  the  customary  way. 


r/eM  Na  1 

Field  No.B 

J5.A 

35  A 

Pasture 

ISA 

Field  Na  J 

Field  No.  "^ 

35  A 

Z5  A 

^ir» 

a      R; 

1 

Fig.    15.     A   farm   mz 


QUESTIONS 

1.  In  what  way  may  a  farm  map  be  used? 

2.  What  is  the  purpose  of  a  sketch  map? 

3.  What  drawing  instruments  are  necessary  for  map  making? 

4.  What  kind  of  paper  should  be  used  in  making  a  map? 

5.  Describe  the  making  of  a  map. 

6.  What  is  the  use  of  conventional  topographical  signs? 


CHAPTER  V 
COMPUTING  AREAS 

Method  of  Computing  Areas.  One  of  the  primary  objects 
in  making  a  farm  survey  is  the  determination  of  the  areas  of 
fields  and  plats.  The  computation  of  areas  as  here  described 
is  dependent  upon  a  knowledge  of  mensuration  and  geometry. 
The  general  plan  to  be  followed  is  to  divide  the  tract  into 
simple  or  primary  figures  whose  areas  can  be  easily  calcu- 
lated. These  familiar  rules  of  mensuration  will  now  be 
reviewed. 

Rectangles.  If  a  tract  of  land  is  rectangular  in  shape, 
its  area  is  found  by  multiplying  its  length  by  its  breadth. 
Triangles.  If  a  piece  of  ground  is  in  the  form  of  a  tri- 
angle, its  area  may  be  obtained  by  either  of  the  following 
rules:  (1)  If  the  length  of  one  side,  and  the  perpendicular 
distance  from  this  side  to  the  opposite  angle,  or  the  altitude 
of  the  triangle,  are  known,  the  area  is  one-half  the  product 
of  the  known  side  as  the  base,  times  the  altitude.  (2)  If  all 
three  sides  of  a  triangle  are  measured, 
then  the  area  may  be  obtained  by 
adding  the  lengths  of  the  three  sides 
and  dividing  the  sum  by  two;  from 
Fig.  16.  this  half  sum  subtract  the  length  of 

each  side  in  turn;  multiply  together  this  half  sum  and  the 
three  remainders;  the  square  root  of  the  product  equals  the 
desired  area.    Thus,  if  a,  h,  and  c  are  three  sides  of  a  triangle, 

,         a  +  fe+c  ,, 
and  s  = ,  then 


area  =  \/     s  {s-a)  (s-b)  (s-c) 


SURVEYING 


35 


Parallelogram.  (Fig.  17.)  The 
area  of  a  parallelogram,  a  four-sided 
figure  with  opposite  sides  parallel,  is 
equal  to  the  product  of  one  of  its  sides 
and  the  perpendicular  distance  be- 
tween it  and  the  opposite  parallel  side. 

Trapezoid.     (Fig.  18.)     This  is  a 
four-sided  figure  with  two  sides  par- 
allel.    The  area  is  equal  to  the  pro- 
duct of  one-half  the  sum  of  the  parallel  ^^^'  ^^" 
sides  by  the  perpendicular  distance  between  them. 


/ 

/[ 

/ 

'•< 

Fig.   17. 
a  >■ 

/ 

/  \ 

\ 

\ 

ff- 

—  4&     >i 

Area 


a+6 


Xh. 


where  a  and  6  are  the  two  parallel  sides,  and  h  the  perpendicular 
distance  between  them. 

Trapeziums  (Fig.  19)  are  quadrilateral  figures,  no  two  of 
whose  sides  are  parallel.  A  practical 
way  to  obtain  the  area  of  a  field  of 
this  shape  is  to  measure  a  diagonal 
dividing  the  field  into  two  triangles 
whose  areas  may  be  calculated.  It 
is  to  be  noted  that  averaging  opposite 
sides  and  taking  their  product  will 
not  give  the  area. 

Area  abcd  =  area  ACD-|-area  abc. 

Figures  With  Many  Sides.  First 
Method:  (Figs.  20  and  21.)  A  many- 
sided  piece  of  land  may  be  likewise 
divided  in  triangles  and  its  area  ob- 
tained in  the  way  described  for  tra- 
pezium. The  triangles  may  be  formed  about  one  of  the 
corners  of  the  figure,  or  about  a  point  wholly  within  the 


Fig.   20. 


36 


AGRICULTURAL  ENGINEERING 


Fig.  21. 


area.     It  is  to  be  noted  that  if  a  point  within  is  taken  as 

the  apex  of  all  the  angles,  it  would 
be  necessary  to  measure,  either  all 
three  sides  of  each  separate  tri- 
angle, or  one  side  of  each  as  a  base, 
and  the  altitude. 

Second  Method:  (Figs.  22  and 
23.)  The  area  of  a  many-sided 
figure  may  be  obtained  by  dividing 
the  field  into  parallelograms  formed 
by  dropping  a  perpendicular  from 
each  corner  to  a  base  line  projected  either  across  the  field  or 

on  one  side.  It  is  to  be 
noted  that  all  parallelo- 
grams which  are  entirely 
outside  of  the  field  are 
negative  areas,  and  their 
sum  should  be  subtracted 
from  the  sum  of  those 
having  a  part  of  their  area  inside 
of  the  field. 

Figures    With  Irregular 
Sides.    First  Method:  The  area 
of  a  field  with  an  irregular  side 
like  that  formed  by  a  stream 
may  be  obtained  by  considering 
the  irregular  side  to  be  formed 
of  short  straight  lines,  and 
measuring  offsets,  or  per- 
pendiculars erected  from 
a  base  line  to  points  in  this 
broken  line  so  as  to  form 


Fig.  23. 


Fig 


trapezoids,  whose  areas  are  easily  found. 


SURVEYING 


37 


Fig.  25. 


Second  Method:  If  the 
side  of  the  irregular  field 
is  not  of  such  a  character 
as  to  be  readily  divided 
into  large  trapezoids,  then 
the  offsets  may  be  taken 
at  regular  intervals  along  the  base  line. 

If  d  be  the  regular  interval  between  offsets  then  the  area  of  the 
trapezoid  whose  sides  are  h  and  h  '  is  equal  to  one-half  their  sum  mul- 
tiplied by  d,  or 

Abea  abcd  =  ]4d  {h-\-h  ') 

PROBLEMS 

1.  What  is  the  area  in  acres  of  a  rectangular  field  whose  length  is 
1320  feet  and  whose  width  is  3473^  feet? 

2.  How  many  acres  in  a  field  80  chains  long  and  13.25  chains  wide? 

3.  What  is  the  area  in  square  feet  of  a  triangular  piece  of  ground,  if 
the  length  of  one  side  is  339  feet  and  the  altitude  on  this  side  as  a  base  is 
92  feet? 

4.  The  length  of  the  sides  of  a  tract  of  land  in  the  form  of  a  tri- 
angle are  220,310,  and  343  feet.     What  is  the  area  in  acres? 

5.  The  four  sides  of  a  trapezium  are  420,  417,  380  and  375  feet 
taken  in  order  around  the  field,  the  diagonal  from  the  comer  between 
the  417  and  the  380  foot  sides  to  the  opposite  comer  is  528  feet.  Find 
the  number  of  acres  in  the  tract. 

6.  Find  the  acre  area  of  a  road  66  feet  wide  and  3960  feet  long. 

7.  Find  the  area  in  square  feet  of  a  tract  of  land  with  an  irregular 
shaped  side  if  offsets  taken  at  the  regular  interval  of  50  feet  are  0,  25, 
30,  28  and  50  feet,  respectively. 

8.  How  many  rows  of  com  3  feet  6  inches  apart  can  be  planted  in 
a  field  20  rods  wide?  How  many  hills  of  com  3  feet  6  inches  apart  wiU 
there  be  in  the  field  if  it  be  80  rods  long? 

9.  How  many  apple  trees  20  feet  apart  may  be  planted  in  a  l-acre 
tract  in  the  form  of  a  square?    Try  a  different  arrangement  of  the  trees. 

10.  At  this  point  the  student  should  be  prepared  to  take  up  the 
problem  of  surveying,  mapping,  and  calculating  the  area  of  certain 
tracts  of  land,  as  the  school  house  yards,  lot,  field,  or  even  whole  farms 


CHAPTER  VI 
THE   UNITED    STATES   PUBLIC   LAND    SURVEY 


In  order  to  facilitate  the  survey,  location,  and  designation 
of  the  lands  in  the  United  States,  Congress  in  1785  adopted 
a  system  since  known  as  the  United  States  Rectangular 
System  of  Public  Land  Surveys.  This  system  has  been 
modified  from  time  to  time,  but  remains  substantially  as 
first  adopted.  The  earth's  surface  is  Uke  that  of  a  sphere, 
and  it  would  be  expected  that  in  attempting  to  lay  out  the 
surface  into  rectangular  areas  one  would  encounter  many 
difficulties.  Yet  these  difficulties  have  been  very  satis- 
factorily met. 

The  squares  of  this  system  are  bounded  on  the  east  and 
west  by  true  meridians  of  longitude,  radiating  from  the 

north  pole,  and  on  the 
north  and  south  by 
chords  of  parallels  inter- 
secting such  meridians. 
A  principal  meridian 
is  chosen  in  each  land 
district,  and  from  this 
meridian  a  base  line  is 
run  east,  west,  or  east 
and  west,  from  what  is 
called  the  initial  point. 
Standard  parallels  are 

Pig.    26.     Showing    the    division    and   num-    PUn    Cast  and  WCSt   frOm 
bering  of  townships.  ,  ...  .  ,.  , 

the  prmcipal  meridian  at 
intervals  of  24  miles.    These  standard  parallels  are  often 

38 


R.4.W 


T.3N. 
R4  W. 


T.2N. 
RAW. 


TIN. 
R.4W. 


T.4N. 
R.iW. 


T.3N. 
RJW. 


T.9N. 
R.3W. 


TIN. 
R.3W. 


T.4N. 
R.SW. 


T.3N. 

R.aw. 


T.SN. 
R.2W. 


TIN. 
R.£W. 


T.4N. 
RJW. 


T.JIM. 
R.IW. 


TEN. 
RJW. 


TIN. 
R.IW, 


Base  Line 


5 


Initial  Point 


SURVEYING 


called  correction  lines.  Guide  meridians  are  run  north  from 
the  base  line  and  from  the  standard  parallels  at  intervals  of 
24  miles.  These  blocks  of  land  are  successively  divided 
into  townships  six  miles  square  and  then  into  sections  ap- 
proximately one  mile  square. 

Townships,  The  townships  lying  between  two  consec- 
utive meridians  six  miles  apart  constitute  a  range,  and  the 
ranges  are  numbered  from  the  principal  meridian,  both  east 
and  west.  The  townships  in  each  range  are  numbered 
both  north  and  south  from  the  base  line.  Thus  if  a  town- 
slip  lies  18  miles  west 
of  the  principal  meridian 
and  12  miles  north  of 
the  base  Hne,  it  is  de- 
scribed as  Township 
(Twp.)  2  N.,  Range  3  W. 
Sections.  Each  town- 
ship is  divided  into  36 
sections  of  1  square  mile, 
or  640  acres  more  or  less, 
the  exact  areas  being 
subject  to  the  conver- 
gence or  divergence  of  f? 
the  meridians,  which 
amounts  to  about  a  foot  for  each  mile. 

Sections  in  all  of  the  more  recent  surveys  are  numbered, 
beginning  with  the  section  in  the  northeast  corner  of  the 
township  as  No.  1,  and  proceeding  as  indicated  in  Fig.  27. 

Subdivisions  of  Sections.  Each  section  may  be  divided 
into  one-fourth  section,  or  160  acres,  or  into  still  smaller 
divisions  of  80,  40,  or  10  acres.  Each  of  these  divisions  may 
be  described  by  its  location  in  the  section.  Thus  a  quarter 
section  of  160  acres  may  be  the  N.E.}^,  S.E.J^,  S.W.M,  or 


6 

5 

4 

J 

' 

/ 

7 

8 

9 

lO 

II 

12 

18 

n 

16 

IS 

14- 

13 

,9 

PO 

ei 

ss 

25 

24- 

zo 

B9 

a6 

Bl 

ee 

SS 

SI 

il 

JJ 

34- 

J5 

Z6 

The    numbering    of    the    sections 
in  the  township. 


40 


AGRICULTUR'AL  ENGINEERING 


160  A 


40A. 


S-i/V./f.-i 

aoA 


Seel 
T4N.R.IW. 


the  N.W.34  of  Sec. — Twp. — Range — .    An  80-acre  tract 

may  be  the  E.3/^,  W.3^,  S.3^,  or  N.^  of etc.    The  40- 

acre  and  smaller  tracts  may  be  described  in  a  similar  manner. 
Monuments.  In  making  the  original  surveys,  the  gov- 
ernment surveyors  left  what  are  called  monuments  to  mark 
the  location  of  principal  comers.  These  monuments  were 
usually  made  of  stone  with  suitable  marks  to  identify  them, 
but  in  some  instances  only  wooden  stakes  or  heaps  of  earth 
were  used. 

Surveys  by  Metes  and  Boiuids.    Before  the  adoption  of 

the  rectangular  system  of 
land  surveying,  the  lands  in 
the  United  States  were  sur- 
veyed by  describing  fully  the 
boundaries,  and  it  was  not 
practical  to  change  to  the 
new  system  where  land  had 
been  so  surveyed.  This  sys- 
tem is  still  used  to  a  certain 
extent  to  describe  small 
tracts  of  land  even  when  the 
rectangular  system  might  be 
used. 

Resurveys.  It  is  not  the  purpose  of  this  text  to  include 
directions  for  surveying  units  larger  than  the  farm,  and  it 
does  not  attempt  to  give  directions  for  a  resurvey  of  the  loca- 
tion of  the  comers  of  a  certain  tract,  yet  some  of  the  impor- 
tant features  of  such  a  survey  may  be  mentioned. 

One  of  the  most  important  considerations  is  that  when  the 
boundaries  of  the  public  lands  established  by  the  authorized 
government  surveyor  are  approved  by  the  surveyor  general, 
and  accepted  by  the  government,  they  are  unchangeable. 
This  is  true  whether  the  comers  were  located  where  they 


Fig.   28.     Divisions  of  the  section. 


SURVEYING  41 

were  intended  to  be  or  not.  Future  surveys  may  be  made 
to  further  subdivide  the  tract,  but  as  long  as  the  original 
corners  are  known,  no  additional  surveys  can  change  them. 
If  the  corners  become  lost,  a  resurvey  may  be  made  to  locate 
them,  not  where  the  corners  ought  to  be  according  to  the 
system,  but  where  they  were  first  located.  There  are  many 
considerations  and  points  to  be  taken  into  account  in  the  re- 
storation of  lost  and  obliterated  corners  and  subdivisions 
of  sections,  and  it  is  advised  that  this  be  left  to  the  pro- 
fessional and  authorized  surveyors. 

QUESTIONS 

1.  What  was  the  purpose  of  the  United  States  rectangular  system 
of  public  land  survey? 

2.  What  is  the  general  plan  of  this  survey? 

3.  Explain  how  the  land  is  divided  into  townships  and  sections. 

4.  How  are  townships  numbered? 
6.  How  are  sections  numbered? 

6.  Explain  how  sections  are  divided  and  the  parts  described. 

7.  How  were  comers  marked  in  the  original  survey? 

8.  Describe  the  process  of  surveying  by  metes  and  bounds. 

9.  What  is  the  purpose  of  a  resurvey? 


CHAPTER  VII 

INSTRUMENTS  FOR  LEVELING 

So  far  our  discussion  has  been  confined  to  instruments 
used  for  measuring  horizontal  distances,  or  those  necessary 
to  obtain  areas.  In  farm  practice,  however,  it  is  necessary 
in  connection  with  drainage  practice,  road  construction,  etc., 
to  determine  vertical  distances,  or  the  height  of  one  point 
above  another  even  though  these  points  be  at  some  hori- 
zontal distance  from  each  other. 

DEFINITION  OF  TERMS 

A  level  surface  is  one  that  is  perpendicular  to  a  plumb 
line  at  every  point  in  the  surface.  It  is  not  a  plane  nor  is  it 
a  true  oblate  spheroid,  owing  to  the  fact  the  earth  is  not  a 
homogenous  body  and  the  center  of  mass  does  not  conform 
with  the  center  of  form. 

A  level  line  is  one  that  lies  wholly  within  a  level  surface. 

A  leveling  instrument  is  one  by  which  a  level  plane  or  a 
level  line  may  be  accurately  determined.  The  three  appli- 
ances upon  which  leveling  instruments  depend  are  the  plumb 
Hne,  a  tube  filled  with  liquid,  and  the  bubble  tube. 

A  datum  plane  or  a  datum  is  the  initial  plane  to  which  the 
height  or  elevation  of  points  may  be  referred.  A  datum 
plane  in  common  use  is  that  of  sea  level. 

The  elevation  of  a  point  is  the  distance  of  the  point  above 
or  below  the  datum  plane. 

A  leveling  rod  is  a  graduated  measuring  rod  or  staff 
used  for  measuring  vertical  distances  between  a  point  on 
which  the  lower  end  of  the  rod  may  rest  and  a  line  indicated 

42 


SURVEYING 


43 


by  an  instrument.  A  leveling  rod  which  has  a  sliding  disk 
or  target  which  may  be  raised  or  lowered  until  the  center  lies 
in  the  Hne  indicated  by  the  leveKng  instrument,  is  called  a 
target  rod.  A  rod  which  may  be  read  from 
a  distance  or  from  the  leveling  instrument 
is  a  speaking  rod. 

Leveling  rods  are  graduated  to  feet,  and 
tenths  and  hundredths  of  a  foot.  In  work 
requiring  extreme  care,  the  target  may  be  so 
made  as  to  be  read  to  one-thousandths  of  a  foot. 

Bench  marks ,  are  permanent  objects 
whose  elevations  are  known  or  assumed, 
and  which  may  be  used  as  reference  marks 
fcr  the  elevation  of  other  points. 

The  Plumb  Line.  The  plumb  line  is  per- 
haps the  simplest  and  most  generally  used 
of  the  leveling  instruments.  Even  the  most 
expensive  instruments  use  the 
plumb  line  to  locate  the  instru- 

,    J.  ,,  .  .     ,  Fig.    29,    Level- 

ment  directly  over  a  given  point,   ing  rods:  the  one 

■r*  ••  11  1  vxi  on   the   right  Is  a 

Provisional  levels  may  be  taken  non-speaking  rod, 
])y  means  of  a  combination  of  the  Ne^^T  "vorlf:  and 
plumb  hne  and  steel  carpenter's  }?/t  is"a^spe"aking 
square,  and  the  difference  in  PhnadTiphia.' '""^ 
the  elevation  of  points  not  far 
apart  may  be  thus  obtained.  This  instrument 
may  be  used  not  only  in  laying  drains  but 
also  in  road  construction  to  determine  the  grade 
of  the  road  and  the  slope  to  the  side  ditches. 
The  U  Tube  or  Water  LeveL  This  instru- 
ment depends  upon  the  principle  that  a  liquid  ** seeks  its 
level."  It  consists  in  two  glass  tubes  fastened  vertically 
about  three  feet  apart  on  a  suitable  arm  and  connected  with 


A  plumb- 
bob  with 
line  attach- 
ed 


44 


AGRICULTURAL  ENGINEERING 


Corks  to  be 

Used  When 

Level  is  Carried 


a  tube.  Water  is  then  poured  in  until  it  appears  at  a  con- 
venient height  in  both  glass  tubes  at  the  same  time.  The 
surface  of  the  water  in  each  of  the  two  tubes  gives  two  points 

in  a  level  line,  which  may 
be  extended  to  a  distant 
leveling  rod  by  sighting 
over  the  surface  of  the 
liquid. 

A  water  level  may  be 
made  as  shown  in  Fig.  31; 
A  and^  are  short  lengths 
of  glass  tubing  attached 
to  a  board,  about  three 
feet  apart,  and  connected 
on  the  lower  sides  with  a 
length  of  rubber  tubing. 
For  field  use,  the  board 
is  bolted  to  a  staff  which 
may  be  pushed  into  the 
ground  to  hold  the  instrument  erect,  and  corks  are  provid- 
ed for  the  upper  ends  of  the  tubes  to  prevent  loss  of  the 
liquid  while  the  instrument  is  being  carried.  When  leveling, 
these  corks  should  be  removed. 

The  bubble  tube    is  the  basis  of  nearly  all    leveling 
instruments.     It  consists  of  a  round  glass  tube  bent  so  that 
the  upper  inside  sur- 
face is   an   arc   of   a      ^ -^^^g^i^^r.g^ /p  fh^bth^.i^. 

circle  lengthwise,  or 
on  a  longitudinal  sec- 
tion.     This   tube  is 

sealed  at  each  end  and  nearly  filled  with  ether,  the 
remaining  space  being  filled  with  the  vapor  of  the  Hquid. 
The    upper    surface    of    the    tube    is    usually    graduated 


Fig.  31.     A  home  made  water  level. 


Fig.   32.     A  bubble   tube. 


SVRVEYINa 


45 


Fig 


A      carpcntor's 
sights  attached. 


level      with 


or  marked  to  indicate  clearly  the  position  of  the  bubble 
in  the  tube. 

If  the  inside  of  the  bubble  tube  is  truly  circular  length- 
wise, then  as  the  bubble  tube  is  held  so  as  to  bring  the  con- 
vex side  of  the  tube  up,  it  is  plain  that  the  bubble  will  come 
to  the  highest  point.  This  being  the  case,  a  hne  tangent  to 
the  curvature  of  the  tube  at  this  point  is  a  level  line  regard- 
less of  the  part  of  the  tube  in  which  the  bubble  may  lie. 

If  the  bubble  tube  is  attached  to  a  frame  and  placed  on 
two  supports  and  one  of  these  supports  is  raised  or  lowered 

until,  as  the  frame  is 
reversed  on  the  supports,  the 
bubble  will  occupy  the  same 
position,  these  supports  are 
both  in  a  level  line,  provid- 
ing the  identical  points  in 
the  frame  come  in  contact  with  the  supports  in  each  case. 
Furthermore,  the  points  on  the  frame  will  be  in  a  level  line 
when  the  bubble  is  brought  into  the  position  described. 

Thus  the  carpenter's  level,  used  for  leveUng  buildings,  is 
made.  If  sights  are  provided  on  the  level,  the  level  line  so 
obtained  may  be  extended  to  a  greater  distance.  A  line 
tangent  to  the  bubble  tube 
on  its  inner  surface  at  its 
center  as  indicated  by  the 
marks  on  the  tube  is  known 
as  the  bubble  axis.  If  the 
bubble  tube  be  revolved 
about  a  line  perpendicular 
to  the  bubble  axis,  the  bub- 
ble axis  will  describe  a  level 
surface. 

The  Level.    The  instrument  used  generally  by  engineers 


Fig.  34.  An  inexpensive  farm  level 
with  horizontal  circle  for  turning  off 
angles. 


46 


AGRICULTURAL  ENGINEERING 


for  determining  the  difference  of  elevation  between  two 
points  is  known  as  the  level,  and  involves  primarily  the  ele- 
ments just  described, — the  bubble  axis,  a  line  of  sight  paral- 
lel to  the  bubble  axis,  and  a  vertical  axis  perpendicular  to  the 
bubble  axis  about  which  it  may  be  revolved. 

To  assist  in  extending  the  line  of  sight,  leveling  instru- 
ments are  provided  with  telescopes.  The  sights  in  this  case 
are  provided  by  cross  wires  or  cross  hairs  set  in  the  tele- 
scope. 


Fig.    35.     A   level   known   as  a  Wye 
level  with  horizontal  circle  and  com- 


dumpy"   level. 


THE  ADJUSTMENTS  OF  THE  LEVEL 
The  Need  of  Adjustment.  Accurate  and  rapid  work 
cannot  be  done  with  a  level  unless  it  be  in  proper  adjustment. 
Even  the  best  instruments  will  not  remain  in  adjustment 
indefinitely,  and  tests  of  their  condition  should  be  made  often. 
In  practice  some  of  the  best  engineers  make  it  a  rule  to  test 
their  instruments  every  day.  Everyone  who  uses  a  level 
should  know  how  to  test  and  adjust  it.  Its  adjustment  is  not 
a  difficult  matter,  yet  it  requires  some  study  to  master  the 
methods  used.  Every  instrument  maker  of  repute  will  fur- 
nish full  and  complete  directions  for  adjusting  each  instru- 
ment of  his  manufacture,  and  these  directions  should  be 
given  preference  over  general  directions  applicable  to  all 


SURVEYING  47 

instruments.  There  is  more  than  one  method  of  making 
certain  adjustments,  but  only  one  will  be  explained  here. 

As  has  been  stated,  there  are  three  elements  in  a  level 
which  should  be  kept  in  proper  relation:  namely,  the  vertical 
axis,  or  the  line  about  which  the  instrument  can  be  rotated; 
the  bubble  axis,  which  is  a  level  line;  and  the  Hne  of  sight. 
The  last  two  must  be  parallel,  and  the  first  perpendicular  to 
both.  If  the  hne  of  sight  be  inclined  upward,  it  is  obvious 
that  all  rod  readings  will  be  too  great,  and  the  error  will  be 
proportional  to  the  distance  of  the  rod  from  the  level.  If  the 
hne  of  sight  be  inclined  do^vnward,  all  readings  will  be  too 
small.  If  the  length  of  sights,  or  the  distance  between  the 
level  and  the  stations,  be  equal  in  making  front  and  back 
sights,  the  error  in  each  case  will  be  the  same,  and  the  rela- 
tive elevation  of  the  stations  will  be  obtained  without  error. 
For  this  reason  it  is  desirable  to  make  fore  sight  and  back 
sight  distances  equal. 

The  adjustment  making  the  vertical  axis  of  the  level  and 
the  bubble  axis  perpendicular,  is  a  matter  of  convenience, 
for  this  will  cause  the  line  of  sight  to  describe  a  plane  con- 
taining all  the  level  lines  through  the  instrument.  This 
means  that  it  will  not  be  necessary  to  change  or  *' level  up'* 
the  instrument  in  sighting  in  different  directions. 

First  Adjustment  To  make  the  vertical  axis  of  instru- 
ment 'perpendicular  to  the  bubble  axis: 

Adjust  the  bubble  tube  to  the  vertical  axis  as  follows: 
Level  up  the  instrument,  bringing  the  bubble  to  the  center 
of  the  tube,  turn  the  telescope  through  180  degrees, 
and,  if  the  bubble  changes  position,  raise  or  lower  the 
adjustable  end  of  the  tube  until  the  bubble  is  brought  half 
^ay  back  to  its  former  position.  Level  the  instrument 
again  and  repeat  the  operation;  and  if  the  bubble  moves  in 
the  tube,  make  further  adjustments.     Continue  this  process 


48  AGRICULTURAL  ENGINEERING 

until  the  bubble  does  not  move  in  the  tube  as  the  telescope 
is  turned  about  the  vertical  axis. 

Second  Adjustment.  To  make  the  line  of  sight  parallel 
to  the  bubble  axis: 

Select  a  level  piece  of  ground  for  the  work,  and  locate 
three  points  in  a  straight  hne,  100  feet  apart.  At  one  end 
point  (Sta.  A)  drive  a  hub,  at  the  mid-point  locate  the  level 
and  take  a  reading  on  a  rod  held  on  the  first  hub  with  the 
instrument  carefully  leveled.  Turn  the  instrument  in  the 
opposite  direction,  and,  after  leveling  carefully,  drive  a  hub 
at  the  second  point  (Sta.  B)  until  the  same  rod  reading  is 
obtained  as  at  Station  A.  These  two  stations  now  have  the 
same  elevation,  because  any  error  of  the  instrument  will  be 
the  same  in  both  cases.  Now  bring  the  instrument  near 
Station  A  (two  or  three  feet  off)  and  adjust  the  line  of  sight 
until  the  same  rod  readings  are  obtained  on  both  stations. 
The  rod  on  Station  A  may  be  read  by  looking  through  the 
instrument  in  the  reverse  way  and  locating  the  line  of  sight 
on  the  rod  with  the  point  of  a  pencil.  After  adjusting,  the 
operation  should  be  repeated  as  a  check. 

QUESTIONS 

1.  Define  a  level  surface.  A  level  line.  A  leveling  instrument.  A 
datum  plane. 

2.  What  is  meant  by  the  elevation  of  a  point? 

3.  Describe  a  leveling  rod.  What  is  the  difference  between  a 
speaking  and  non-speaking  rod? 

4.  How  are  leveling  rods  graduated? 

5.  What  is  the  purpose  of  a  bench  mark? 

6.  Describe  the  plumb  line.  How  may  it  be  used  to  determine  a 
level  line? 

7.  Describe  the  construction  of  the  water  level. 

8.  Describe  the  bubble  tube  and  its  use  in  leveling. 

9.  Describe  the  construction  of  the  engineer's  level. 

10.  What  is  meant  by  the  "line  of  sight"? 

11.  Describe  the  fundamentals  of  the  adjustment  of  the  level 


CHAPTER  VIII 
LEVELING  PRACTICE 

Differential  Leveling.  Differential  leveling  is  the  name 
given  to  the  process  of  finding  the  difference  of  elevation  of 
two  or  more  points  at  some  distance  from  each  other,  with- 
out reference  to  intermediate  points  except  those  required 
temporarily  in  carrying  a  line  of  levels  between  the  points 
whose  difference  of  elevation  is  required.  Differential 
leveling  is  hke  profile  leveling,  except  that  elevations  are 
not  taken  at  regular  intervals  on  the  surface.  It  is  desir- 
able, however,  to  make  the  sights  or  the  distances  between 
the  instrument  and  rod  of  equal  length,  as  this  tends  to  equal- 
ize errors  which  may  exist  in  the  adjustment  of  the  instru- 
ment. 

Profile  Leveling.  Profile  leveling  is  for  the  purpose  of 
obtaining  the  elevations  of  the  surface  of  the  ground.  It  is 
especially  important  in  this  connection,  as  profile  leveling 
is  required  in  the  laying  out  of  land  drainage  systems. 

Leveling.  The  process  of  leveling,  or  in  other  words  the 
performance  of  the  field  work  in  determining  the  elevation 
of  points  on  the  surface  of  the  ground,  is  comparatively 
simple,  yet  it  is  highly  important  that  the  work  be  done 
accurately  and  that  a  full  record  be  made  of  the  work. 

To  run  a  line  of  levels,  a  bench  mark,  or  a  permanent  point 
of  reference,  should  be  chosen  from  which  a  start  is  made. 
The  importance  of  the  bench  mark  is  all  the  more  magnified 
with  an  increase  in  the  size  of  the  system  of  levels.  If  the 
elevation  of  the  bench  mark  is  not  known,  it  must  be  assumed. 
For  convenience  it  is  usually  taken  as  10,  20,  or  100  feet, 

4U 


50 


AGRICULTURAL  ENGINEERING 


depending  somewhat  upon  whether  the  levels  are  to  be  taken 
above  or  below  the  elevation  of  the  bench  mark. 

As  for  field  surveying,  a  substantial  field  book  should  be 
provided  for  level 
notes.  A  book  of  the 
same  size  as  previ- 
ously suggested  is  de- 
sirable, with  ruling  as 
shown  in  Fig.  37.  The 
elevationof  the  bench 
mark  is  placed  in  the 
second  column  oppo- 
site the  entry  B.  M. 
in  the  first  column. 

Set  the  instrument  up  half  way  between  the  bench  mark 
and  the  first  point  whose  elevation  is  desired  in  the  line  of 
levels.  This  point  is  called  Station  A,  and  is  entered  as  such 
in  the  first  column  of  the  field  book.    After  the  instrument  is 


L/ne   of  Levels. 

5fa 

B.S. 

HI. 

r.s. 

Elev. 

BM. 

6.50 

leso 

10.00 

A 

1.00 

ig.4o 

4:10 

18.40 

B 

4.05 

3135 

a.  10 

11.20 

C 

3.60 

11.15. 

Fig.    37.     A  form  for   level   notes. 


10.00 


Fig.    38.     Sketch    illustrating   the    levels    of   Fig.    37. 


brought  into  a  level  position,  the  rodman  holds  the  rod  in  a 
vertical  position  over  the  bench  mark,  and  the  levelman  takes 
a  reading  by,  over,  or  through  the  instrument  to  the  rod.  The 
reading  thus  obtained  is  the  distance  of  the  line  of  sight 
above  the  bench  mark  (B.  M.),  as  the  rod  is  graduated  from 
the  bottom  up  and  the  line  of  sight  is  a  level  line.    This 


SURVEYING  51 

reading  is  called  a  back  sight  (B.  S.),  and  if  added  to  the 
elevation  of  the  bench  mark  will  give  the  elevation  of  the 
instrument,  or  the  height  of  instrument  (H.  I.),  as  generally 
designated.  The  first  B.  S.  thus  obtained  is  entered  in  the 
notes  in  the  second  column,  opposite  the  B.  M.  elevation 
in  the  first.  This  B.  S.  plus  the  elevation  of  the  B.  M.  is 
entered  in  the  third  column  under  the  head  of  height  of 
instrument,  or  H.  I. 

Thus  if  the  elevation  of  the  B.  M.  be  assumed  as  10.00 
feet,  and  the  B.  S.  reading  of  the  instrument  on  this  point 
be  6.50  feet,  the  H.  I.  will  be  16.50  feet. 

Now  if  the  instrument  be  turned  so  as  to  extend  the  line 
of  sight  in  the  direction  of  the  first  point  in  the  line  of  levels 
(Sta.  A)  and  a  reading  be  taken  in  the  same  way,  the  reading 
on  the  rod  will  be  the  distance  of  the  elevation  of  this  point 
below  the  line  of  sight.  The  reading  is  called  a  fore  sight 
(F.  S.),  and  is  entered  in  the  fourth  column  opposite  Station 
A.,  on  which  the  reading  was  taken.  If  this  fore  sight  read- 
ing be  subtracted  from  the  elevation  of  the  line  of  sight 
(H.  I.),  the  elevation  of  Station  A  will  be  obtained.  For 
instance,  suppose  the  F.  S.  reading  thus  obtained  is  4.10 
feet,  then  H.  I.,  16.50  feet,  minus  the  F.  S.,  4.10  feet,  equals 
12.40  feet,  the  elevation  of  Station  A,  which  is  entered  in  the 
proper  column  opposite  Station  A. 

To  continue  the  line  of  levels,  the  instrument  is  moved  to 
a  position  midway  between  Station  A,  and  Station  B, 
and,  after  the  instrument  is  leveled,  a  B.  S.  reading  is  made 
on  Station  A.  This  reading  added  to  the  elevation  of 
Station  A  gives  a  new  H.  I.,  from  which  the  F.  S.  reading  on 
Station  B  is  subtracted  to  obtain  the  elevation  of  Station  B. 

Thus  the  process  is  continued  until  the  elevations  of  all 
the  points  in  the  line  of  levels  are  obtained.  It  is  easy  to  see 
how  additional  readings  may  be  taken  with  the  same  height  of 


62 


AGRICULTURAL  ENGINEERING 


instrument  and  thus  obtain  the  elevation  of  several  points 
between  A  and  B.     This  is  done  in  practice. 

It  is  to  be  noted  in  this  connection  that  back  sights  are 
rod  readings  on  stations  or  points  whose  elevations  are  known, 
and  fore  sights  are  readings  on  stations  whose  elevations  are 
liQt  known.  Stations  on  which  back  sights  are  taken  are 
generally  known  as  turning  points. 

Stakes.  It  is  generally  best  that  all  stations  be  marked 
with  a  stake  driven  down  close  to  the  ground,  on  which  the 

levehng  rod  may  be  placed; 
and  turning  points  should 
always  be  so  marked  and 
identified. 

Leveling  a  Field.  It  is 
sometimes  advisable  to  obtain 
levels  at  regular  intervals 
over  an  entire  field.  This  is 
accomplished  by  laying  the 
field  off  into  squares,  usually 
by  the  chain  or  tape.  The 
squares  are 
marked  with  stakes  made  of 
lath  and  the  elevation  of  the 
top  of  the  ground  is  taken  at  each  corner,  as  shown  in  Fig.  39. 
The  various  corners  of  the  squares  are  designated  by  lettering  in 
one  direction  and  numbering  in  the  other  as  shown  in  the  figure. 
Contour  Maps.  Lines  may  be  drawn  over  the  map  of 
the  leveled  field  to  indicate  points  of  equal  elevation.  Such 
lines  are  called  contour  fines.  They  offer  a  very  satisfactory 
means  of  studying  the  surface  of  the  ground,  and  a  map  so 
prepared  is  especially  useful  in  laying  out  drainage  systems. 
Horizontal  Circles  for  Levels.  Many  levels  are  pro- 
vided with  horizontal  circles  or  scales,  graduated  in  degrees 


/3.0 

/2.9      / 

2  8 

/ZS 

/2^        / 

>2.3 

/2.3 

/SO 

'Z.O 

//^ 

/Zy 

/Z2 

/z/ 

//.a 

//■r 

//.O 

//.8 

//.8 

//£> 

//7 

//.7 

//.6 

//ff 

//3 

//^, 

//^ 

//5 

//3 

//./ 

//.-f 


/// 

6 


Fig.    39.     Plat    showing    how    levels     pnrr»Ar«    r»f    \\\pk 
may    be    taken    over    an    entire    field.     ^'J^^^t^io    ^^     ^^^^ 
The    stations    are    indicated    by    letter 
and  numbers,  as  Bz,  etc. 


SURVEYING  53 

and  fractions  of  degrees,  which  enable  the  angle  between 
lines  of  sight  in  different  directions  to  be  measured.  This 
device  is  especially  useful  in  laying  off  right  angles,  as  well  as 
in  obtaining  the  angle  between  two  sides  of  a  tract  of  land, 
and  between  Hues  of  drains  in  laying  out  drainage  systems. 

The  Compass.  A  level  may  be  provided  with  a  compass 
box  containing  a  magnetic  needle,  which  will  enable  the  angle 
to  be  measured  between  any  hne  of  sight  and  the  north  and 
south  as  indicated  by  the  needle.  In  construction,  the  mag- 
netic needle  is  a  fine  hardened  piece  of  steel  carefully  balanced 
and  hung  on  a  delicate  pivot  and  so  arranged  as  to  swing 
within  a  graduated  circle.  In  order  to  protect  the  pivot 
while  the  instrument  is  being  carried  about,  a  little  device 
is  provided  to  fift  the  needle  from  the  pivot.  In  most 
localities  the  needle  does  not  point  truly  north  and  south, 
inasmuch  as  the  magnetic  pole  does  not  always  He  due  north; 
and  furthermore,  the  location  of  the  magnetic  pole  varies 
from  time  to  time.  If  the  true  north  is  desired,  it  is  neces- 
sary to  make  the  corrections  for  the  location  of  the  magnetic 
pole.  This  variance  from  the  true  north,  or  meridian,  is 
called  the  declination  of  the  needle.  In  reading  the  needle, 
if  no  correction  is  made,  it  is  customary  to  indicate  that  the 
reading  is  magnetic  (Mag.). 

The  Bearing  of  a  Line.  The  direction  of  a  line  is  called 
its  bearing;  in  other  words,  the  bearing  is  the  angle  that  a  line 
makes  with  the  direction  of  the  magnetic  needle.  If  the 
direction  of  a  line,  beginning  with  the  instrument,  lies  within 
90  degrees  to  the  right  or  the  left  of  the  needle,  it  is  said  to 
have  a  north  bearing,  or  a  northing;  and  likewise,  if  it  lies 
within  90  degrees  of  the  true  south,  either  east  or  west,  it  is 
said  to  have  the  south  bearing,  or  a  southing.  If  the  line 
lies  to  the  east  of  north,  it  is  also  said  to  be  east,  and  if  to  the 
west,  it  is  said  to  be  west,  and  is  so  designated  following  the 


54 


AGRICULTURAL  ENOINEERINO 


number  of  degrees  indicating  the  angle  of  the  line  with  the 
true  north  or  south.  Thus,  a  line  in  the  right-hand  quadrant 
is  north  and  so  many  degrees  east;  as,  N.  4°  37  '.  E.  A  hne 
whose  direction  lies  in  the  left-hand  quadrant  is  north,  and 
so  many  degrees  west. 

The  Transit.     It  is  not  the  purpose  to  include  here 

instructions  in  the  use  of  the 
transit.  It  is  desirable,  how- 
ever, to  explain  in  a  brief  way 
the  instrument.  The  transit  is 
a  universal  surveying  instru- 
ment, and  it  is  arranged  for 
measuring  horizontal  and  verti- 
cal angles,  for  determining  the 
bearings  by  the  magnetic  needle, 
for  leveling,  for  measuring  dis- 
tances by  means  of  an  attach- 
ment known  as  stadia  wires, 
and  for  determining  bearings 
from  the  sun  when  provided 
with  a  suitable  solar  attach- 
ment, and  for  many  other  lines 
of  work. 
PROBLEMS 


Fig.   40.     A  surveyor's  transit. 


The  instructor  should  here  arrange  practice  work  in  differential 
and  profile  leveling,  and  surveying  with  the  horizontal  circle  and  com- 
pass as  far  as  the  equipment  provided  will  permit. 

QUESTIONS 

1.  What  is  meant  by  differential  leveling? 

2.  What  is  the  purpose  of  profile  leveling? 

3.  Describe  the  process  of  leveling. 

4.  How  should  level  notes  be  recorded  in  the  field  book? 

5.  What  is  meant  by  a  back  sight?  Height  of  instrument? 
Fore  sight? 


SURVEYING  55 

6.  Describe  the  process  of  leveling  a  field. 

7.  What  is  a  contour  map? 

8.  What  is  the  use  of  the  horizontal  circle  found  on  some  levels? 

9.  Describe  the  compass. 

10.  What  is  meant  by  the  "declination  of  the  needle?" 

11.  What  is  the  "bearing"  of  a  line? 

12.  Describe  the  surveyor's  transit,  and  for  what  may  it  be  used? 

REFERENCE  TEXTS 

The  Theory  and  Practice  of  Surveying,  J.  B.  Johnson. 
A  Manual  of  Field  and  Office   Methods  for  the  Use  of  Students  in 
Surveying,  William  D.  Pence  and  Milo  S.  Ketchum. 
Plane  Surveying,  John  Clayton  Tracy. 


PART  TWO— DRAINAGE 


CHAPTER  IX 
PRINCIPLES  OF  FARM  DRAINAGE 

Regulation  of  Soil  Water.  All  vegetation  is  dependent 
upon  the  water  or  moisture  in  the  soil  for  life  and  growth. 
Water  dissolves  the  plant  food  in  the  soil  and  enables  the 
plant  to  absorb  and  circulate  it  throughout  its  structure. 
Water  also  being  transpired  or  given  out  by  the  plant,  has  a 
coohng  effect,  which  counteracts  the  heat  of  the  burning 
sun  and  prevents  the  plant  from  being  withered  or  burned 
up.  The  amount  of  water  used  by  plants  for  their  most 
satisfactory  growth  is  called  the  duty  of  water.  Nature  does 
not  always  supply  water  to  the  soil  in  quantities  conducive 
to  the  most  satisfactory  growth  of  the  plant.  Often  there  is 
too  little  water,  and  many  times  there  is  too  much.  Land 
is  drained  for  the  purpose  of  relieving  the  soil  of  the  surplus 
water. 

History  of  Drainage.  The  practice  of  land  drainage 
runs  back  to  a  very  early  date.  Some  of  the  most  interest- 
ing drainage  projects  of  early  times  are  the  drainage  of  the 
fens  of  England  and  of  Haarlem  Lake  in  Holland.  Land 
drainage  by  means  of  tile  was  introduced  in  Europe  as  early 
as  1620,  but  it  did  not  come  into  general  use  until  about  1850. 
Land  drainage  by  tile  was  begun  in  the  United  States  as 
early  as  1835,  by  John  Johnson,  a  farmer  of  Geneva,  New 
York.  These  early  drain  tiles  were  made  by  hand.  Tile- 
making  machines  were  introduced  about  1848,  and  from  this 
time  on,  tile  drainage  increased  rapidly. 

66 


DRAINAGE 


57 


The  area  of  the  land  in  the  United  States  which  may  be 
improved  by  drainage  is  still  large.  It  is  estimated  by  Mr. 
C.  G.  EUiott,  formerly  Chief  of  Drainage  Investigation, 
United  States  Department  of  Agriculture,  that  there  are 
yet  70,000,000  acres  of  land  in  the  United  States  to  be 
reclaimed  by  drainage.  In  addition  to  this  there  are  large 
areas  of  land  which  could  be  made  more  productive  and  more 
valuable  by  drainage. 

Water  in  the  Soil.  The  water  in  the  soil  may  be  classified 
as  capillary  water  and  hydrostatic  water.     Capillary  water 


Fig.    41. 


Land  needing   drainage.      Typical   conditions   in   northern   Iowa 
and   southern    Minnesota. 


is  that  which  covers  the  surface  of  the  soil  particles  or  grains 
as  a  film.  It  is  the  water  in  the  soil  which  moves  toward  the 
surface  by  capillarity  as  the  water  at  the  surface  evaporates. 
Hydrostatic  water,  or  ground  water,  is  that  which  fills  the 
open  spaces  between  the  soil  particles  and  which  obeys  gravity 
to  the  extent  that  it   may   be  drawn  off  at  the  bottom 


58 


AGRICULTURAL  ENGINEERING 


of  a  layer  of  soil  if  a  suitable  outlet  be  provided.  When 
water  exists  on  soil  particles  in  a  very  finely  divided  state  it 
is  often  called  hygroscopic  water.  It  is  understood  that 
capillary  water,  as  defined,  would  include  this  hygroscopic 
water  or  moisture. 

Lands  Requiring  Drainage.     In  general,  land  having  an 


Fig.  42.    A  good  crop  of  corn  on  land  which  was  a  swamp  the  year  before. 

excess  of  water  over  that  required  to  furnish  the  best  con- 
ditions for  plant  growth,  needs  under  drainage.  The  exact 
conditions  prevailing  when  an  excess  is  present  may  be  out- 
lined as  follows: 

1.  Comparatively  flat  land  in  which  water  collects  in 
basins  or  ponds  from  the  higher  surrounding  land. 


DRAINAGE  59 

2.  Land  kept  continually  wet  by  water  appearing  at  the 
surface,  having  seeped  or  passed  underneath  the  surface 
from  land  at  a  higher  level.  Such  a  condition  is  due  to  the 
action  of  springs. 

3.  Flat  land  underlaid  with  an  impervious  stratum  of 
clay  which  prevents  the  water  from  sinking  downward 
through  the  soil.  Often  this  condition  is  represented  by  an 
old  lake  bottom. 

4.  Lands  on  which  certain  crops  are  grown,  such  as  rice 
fields  or  meadow  lands,  to  which  irrigation  water  may  be 
applied  and  removed  at  will. 

5.  Lands  subject  to  overflow  by  rivers  or  tides. 

Kinds  of  Soils.  The  kind  of  soil  to  be  drained  must  by 
all  means  be  considered  in  connection  with  the  planning  of 
farm  drainage.  The  amount  of  capillary  water  that  the 
soil  will  hold  varies  largely  with  the  fineness  of  the  particles; 
but  a  very  fine  soil  will  not  allow  water  to  pass  through  it 
quickly,  and  for  that  reason  is  designated  as  a  retentive  soil. 
There  are  other  factors  involved  besides  the  fineness  of  the 
soil  particles;  for  example,  the  working  or  mixing  of  a  finely 
divided  soil,  such  as  clay  soil,  while  filled  with  water  tends  to 
make  it  impervious,  or  water-tight. 

An  open  soil  is  one  through  which  the  water  will  pass 
quickly,  and  in  which  the  pore  space  is  not  so  finely  divided 
as  in  a  retentive  soil.  The  volume  of  the  space  between  the 
soil  particles  may  be  greater  in  the  retentive  soil  than  in  the 
open  soil,  as  this  space  generally  increases  with  the  fineness  of 
the  particles. 

Kinds  of  Under  drainage.  All  soils  need  underdrainage, 
that  is,  the  hydrostatic  or  ground  water  should  be  drawn 
ofif  from  the  soil  in  some  way.  In  most  cases  this  under- 
drainage is  provided  by  nature,  and  the  ground  is  said  to  have 
natural  underdrainage.    The  same  may  be  true  where  the 


60 


AGRICULTURAL  ENGINEERING 


surface  of  the  ground  is  such  as  to  give  good  surface  drainage, 
as  where  the  land  has  a  good  slope.  However,  where  natural 
underdrainage  is  not  provided,  or  where  the  surface  is  such 
as  not  to  provide  surface  drainage,  artificial  drainage  should 
be  installed  by  means  of  tile  drains  or  open  ditches. 

Underdrains.  Artificial  underdrainage  is  generally 
accomplished  by  providing  conduits,  as  open  pipes,  which 
will  provide  a  free ,  and  as  far  as  possible,  an  unobstructed 


Fig.   4  3.      An  open  drain. 

passage  for  the  flow  of  the  water  through  the  soil.  To 
secure  the  best  results,  these  tile  lines  should  have  as  much 
fall  or  slope  as  is  practical  in  order  to  give  a  high  velocity  of 
flow  to  the  water  within  them,  and  they  should  be  as  straight 
as  possible  and  free  from  sags  and  obstructions. 

Open  Drains.  Open  drains  or  ditches  are  simply  free, 
open  channels  for  the  flow  of  water,  where  large  quantities 
are  to  be  cared  for.  They  are  used  where  a  system  of  under- 
drainage made  of  tile  would  not  be  practical.    The  ad  van- 


DRAINAGE  61 

tages  of  closed  or  underdrainage,  where  it  may  be  used,  are 
obvious.  It  does  not  interfere  with  the  cultivation  of  crops 
or  other  operations  conducted  on  the  land. 

Benefits  of  Drainage.  Preparatory  to  the  installation 
of  the  farm  drainage  system,  must  come  the  consideration  of 
the  benefits  to  be  derived  and  an  estimate  to  determine  the 
advisability  of  the  expenditure  required,  from  the  stand- 
point of  an  investment.  Certain  drainage  systems  may  be 
justified  as  a  protection  to  the  health  of  the  people  of  the 
neighborhood.  This  value  cannot  be  computed  in  dollars 
and  cents.  Yet  most  farm  drainage  must  be  considered  from 
the  business  standpoint.  In  this  connection  full  considera- 
tion should  be  given  to  all  of  the  benefits  which  may  be 
derived  from  the  improvement  of  the  land  by  drainage.  In 
general,  it  is  to  be  expected  that  drainage  will  either  reclaim 
the  land  for  farming  purposes  or  make  it  more  productive. 
There  are  various  ways  in  which  land  is  made  more  produc- 
tive by  drainage. 

Soil  is  Made  Firm.  When  the  level  of  the  hydrostatic 
water  is  lowered,  the  soil  above  becomes  more  firm.  Thus  the 
wet  marshy  field  in  which  a  horse  would  mire  may  be  made 
so  firm  by  drainage  as  to  permit  a  team  and  load  to  pass  over 
it  safely. 

Soil  is  Made  of  Finer  Texture.  It  has  been  proven  con- 
clusively that  drainage  causes  the  soil  to  become  divided 
into  smaller  particles,  thus  enabling  it  to  hold  a  larger  amount 
of  capillary  water.  The  agents  which  bring  about  a  disin- 
tegration of  the  soil  particles  in  underdrained  soil  are  the 
percolation,  or  passing  of  the  water  down  through  it,  and  the 
action  of  air  and  frost. 

The  Growing  Season  Is  Lengthened.  Drainage  lessens 
the  amount  of  water  that  evaporates  from  the  surface  and 
the  amount  in  the  soil  to  be  raised  in  temperature,  permitting 


62  AGRICULTURAL  ENOINEERINa 

the  soil  to  warm  up  earlier  in  the  spring,  and  to  remain  warm 
later  in  the  fall,  thus  indirectly  increasing  the  length  of  the 
growing  season.  The  cooling  effect  of  the  evaporation  of 
water  is  known  to  all. 

The  Soil  Temperature  Is  Raised.  In  a  manner  similar 
to  that  just  explained,  the  soil  is  maintained  at  a  warmer 
temperature  throughout  the  growing  season,  assisting  in  the 
rapid  growth  of  plants. 

Ventilation.  Underdrainage  causes  the  soil  to  be  aerated ; 
for  as  soon  as  the  hydrostatic  water  is  drawn  away  by  the 
drains,  the  space  between  the  soil  particles  is  filled  with  air. 
This  has  a  beneficial  effect,  since  all  plants  require  some  air. 

Prevents  Surface  Wash.  When  the  hydrostatic  water 
of  the  soil  is  drawn  away  by  underdrainage,  the  soil  is  in  a 
condition  to  receive  a  very  heavy  rainfall  before  the  water 
will  run  off  over  the  surface ;  or,  in  other  words,  underdrainage 
will  enable  the  soil  to  provide  a  large  reservoir  for  rain  water. 

Increases  the  Depth  of  Soil.  As  the  soil  becomes  warmer 
and  aerated,  the  roots  strike  deeper,  thus  increasing  the 
depth  of  the  soil  available  for  plant  food. 

Drouth.  Strange  as  it  may  seem,  well-drained  soil 
resists  drouth  better  than  wet.  The  greater  fineness  and 
depth  of  the  soil  enable  it  to  retain  a  larger  amount  of  capil- 
lary water,  which  is  the  water  chiefly  used  by  plants. 

The  Action  of  Frost  Is  Reduced.  Soil  which  is  filled  with 
hydrostatic  water  expands  upon  freezing  and  is  said  to 
"heave."  Although  the  action  of  frost  may  be  beneficial, 
as  previously  explained,  heaving  is  very  injurious  to  certain 
crops  which  are  planted  in  the  fall.  If  the  ground  water  of 
the  soil  is  drained  out,  this  action  is  almost  entirely  over- 
come. 


DRAINAGE  63 

QUESTIONS 

1.  Why  is  water  so  necessary  to  plant  life  and  growth? 

2.  What  is  meant  by  "duty  of  water?" 

3.  What  is  the  purpose  of  land  drainage? 

4.  When  was  tile  drainage  introduced  in  the  United  States,  and  by 
whom? 

5.  How  many  acres  may  be  reclaimed  by  drainage  in  the  United 
States? 

6.  Explain  what  is  meant  by  capillary  water.     Hydrostatic  water. 

7.  Give  and  explain  five  conditions  of  land  needing  drainage. 

8.  What  is  the  difference  between  an  open  and  a  retentive  soil? 

9.  How  is  artificial  underdrainage  secured? 

10.  When  are  open  drains  advisable? 

11.  Explain  eight  primary  benefits  of  drainage. 


CHAPTER  X 
THE  PRELIMINARY  SURVEY 

The  Drainage  Engineer.  The  services  of  a  professional 
drainage  engineer  are  well  worth  their  cost.  The  success  of 
any  drainage  system  depends  upon  whether  it  is  well  planned 
or  not.  If  not  correctly  installed,  the  whole  investment  may 
be  worthless.  Hence  a  small  percentage  of  this  investment 
paid  in  fees  to  those  who  by  training  and  experience  know  how 
the  work  should  be  done  is  money  well  spent.  It  is  not  the 
purpose  of  this  text  to  detract  from  the  work  of  the  engineer, 
but  rather  to  lead  to  an  appreciation  of  his  work. 

There  is  a  difference  between  surveying  and  engineering. 
Surveying  includes  only  the  taking  and  recording  of  such 
field  observations  necessary  for  the  designing  of  a  drainage 
system.  The  actual  work  involved  in  the  designing  and 
execution  may  truly  be  called  engineering.  This  latter  work 
involves  much  skill  and  experience. 

The  Need  of  a  Preliminary  Survey.  The  first  step  in 
the  drainage  of  any  tract  of  land  is  the  making  of  a  prelimi- 
nary survey  or  an  investigation,  which  should  be  for  the 
purpose  of  obtaining  a  clear  idea  of  the  situation  and  a 
general  knowledge  of  the  nature  and  amount  of  drainage 
which  will  be  required  to  accompHsh  the  desired  purpose. 

The  prehminary  survey,  then,  is  the  basis  upon  which  the 
next  step,  involving  the  actual  work  of  installing  the  drain- 
age system,  must  depend.  There  are  many  things  to  be  con- 
sidered in  the  preliminary  survey,  such  as  information  con- 
cerning the  character  and  value  of  the  land  before  and  after 
improving.     Careful    investigations    should    be    made    to 

64 


DRAINAGE  65 

determine  if  possible  the  fertility  of  the  land  after  improving. 
Then  the  drainage  engineer  should  go  over  the  tract  in  order 
that  he  become  thoroughly  familiar  with  it  before  under- 
taking any  instrument  work  at  all.  If  the  tract  is  large  and 
if  the  ownership  is  divided,  care  should  be  taken  that  all 
work  from  the  outset  shall  conform  to  the  law  of  the  state  in 
which  the  tract  is  located. 

The  Extent  of  the  Survey.  In  the  drainage  of  all  but  the 
smallest  areas  it  is  quite  necessary  to  make  the  preliminary 
survey  before  attempting  in  any  way  to  decide  upon  the  final 
plan.  The  piu-pose  of  the  preliminary  survey  is  to  obtain  the 
data  from  which  the  final  plans  must  be  made.  The  data 
secm"ed  should  include  the  area  of  the  drainage  basin, 
location  of  the  water-shed,  direction  of  the  slopes  and  water 
courses,  and  should  indicate  soil  conditions  and  possible 
outlets. 

In  securing  this  data  it  is  necessary  that  the  work  be  done 
carefully.  Mistakes  are  costly  and  can  only  be  avoided  by 
careful  work  in  securing  correct  information  in  the  prelim- 
inary survey.  Careful  work  with  crude  instruments  is  often 
more  satisfactory  than  hasty  work  with  expensive  equip- 
ment. 

Investigation  of  the  Subsoil.  An  investigation  of  the 
character  of  the  soil  and  subsoil  should  be  made  a  part  of  the 
preliminary  survey,  for  on  the  data  thus  secured  will  depend, 
to  a  large  extent,  the  depth  of  and  distance  between  tile 
lines.  This  is  quite  important  in  land  that  is  imderlaid 
with  sand  and  gravel  or  with  an  impervious  stratum  of  clay. 
These  investigations  can  best  be  made  with  the  soil  auger. 
This  tool  can  be  made  by  welding  a  long  handle  to  an  ordinary 
IJ^  or  2-inch  carpenter's  auger.    See  Fig.  53. 

Preliminary  Instrument  Work.  An  engineer's  level 
should  be  used  in  the  preUminary  survey  to  obtain  elevations 

3— 


66  AGRICULTURAL  ENGINEERING 

which  will  show  definitely  the  lay  of  the  land.  It  is  not  safe 
for  even  the  most  experienced  to  estimate  slopes  by  the 
naked  eye. 

Map  of  the  Preliminary  Survey.  A  sketch  or  map 
should  be  made  indicating  the  location  and  elevation  of  the 
low  and  wet  areas  in  the  land,  and  also  the  watershed.  In 
some  cases  where  the  land  is  quite  fiat  it  is  desirable  to  take 
levels  at  regular  intervals  over  the  entire  tract,  and,  perhaps, 
to  prepare  a  contour  map  as  explained  in  a  previous  chapter. 
With  this  information  it  is  possible  to  lay  out  the  drainage 
system,  if  conditions  show  that  a  practical  system  is  possible. 

It  is  desired  to  lay  special  emphasis  upon  the  importance 
of  this  preHminary  survey.  The  quite  common  practice  of 
laying  tile  largely  by  guess,  without  a  consideration  of  the 
land  area  to  be  drained  or  the  capacity  of  the  tile,  cannot  be 
too  severely  criticised.  The  large  amount  of  insufficient 
and  unsatisfactory  drainage  to  be  found  everywhere  is  silent 
testimony  to  the  statement  that  tile  drainage  must  be  done 
carefully  and  intelHgently. 

QUESTIONS 

1.  What  is  the  purpose  of  a  preliminary  survey? 

2.  Why  should  a  drainage  engineer  be  employed  on  important 
work? 

3.  What  is  the  difference  between  surveying  and  drainage  engineer- 
ing? 

4.  What  should  be  included  in  the  preliminary  survey? 

5.  Why  should  the  subsoil  be  investigated? 

6.  To  what  extent  should  an  instrument  be  used  in  a  preliminary 
survey? 

7.  What  should  be  included  in  the  map  of  the  preliminary  survey? 


CHAPTER  XI 
LAYING  OUT  THE  DRAINAGE  SYSTEM 

Definitions  of  Terms.  Before  beginning  a  discussion  of 
drainage  systems  it  is  well  that  the  meaning  of  some  of  the 
common  terms  used  in  connection  therewith  be  explained. 

The  discharge  end  of  the  tile  line  or  main  is  called  the 
outlet,  and  the  upper  or  upstream  end  is  called  the  head. 
The  term  lateral  is  used  for  the  single  tile  line  with  no 
branches.  The  main  is  the  line  of  large  tile  that  carries  the 
discharge  from  a  number  of  laterals.  If  the  discharges  from 
several  laterals  are  received  into  a  larger  tile  line  before  it 
reaches  the  main,  the  line  which  receives  the  discharge  from 
the  laterals  is  spoken  of  as  the  submain.  It  is  customary  to 
designate  the  laterals  and  submains  by  number  and  the 
mains  by  letter. 

Direction  of  Drains.  As  a  rule,  all  drains  should  parallel 
the  slope  of  the  surface.  The  surface  of  the  ground  water 
is  usually  parallel  to  the  surface  of  the  ground  and  flows 
down  the  slope.  If  tile  be  laid  across  the  direction  of  the 
slope,  it  will  not  receive  any  water  from  the  ground  below 
the  line,  and  in  fact  some  water  from  above  may  flow  past 
the  tile  line.  Rarely  the  lines  may  be  laid  across  the  slope 
to  intercept  a  seepage  flow  or  to  drain  pockets  in  sub-surface 
strata. 

Depth  of  Tile  Drains.  Except  in  very  retentive  soil 
through  which  the  water  does  not  percolate  rapidly,  the  tile 
should  be  placed  at  a  good  depth.  It  takes  little  time  for 
the  water  to  pass  straight  down  to  a  tile,  but  it  takes  more 
time   for   it   to   flow   horizontally   through   the   soil.     By 

67 


68 


AGRICULTURAL  ENGINEERING 


placing  a  tile  deep,  a  large  reservoir  is  provided  for  rainfall, 
and  the  tile  will  have  a  longer  time  to  carry  the  surplus  away. 
Distances  between  Drains.  It  is  a  practice  in  some 
localities  where  an  average  soil  exists,  to  consider  that  tile 
will  drain  the  water  from  the  soil  to  a  distance  of  one  rod  for 
each  foot  in  depth.  As  the  ground  water  flows  away  through 
the.  tile  lines  after  heavy  rains,  the  level  of  the  ground  water 
is  first  lowered  directly  over  and  near  the  tile,  which  causes 
side  flow  of  the  water  through  the  soil.  If  the  soil  is  open  or 
sandy,  this  flow  through  the  soil  is  rapid,  and  the  level  of  the 


Fig.  44.     Sketch  showing  how  the  ground  water  is  lowered  and  the  capacity 
of  the  soil  as  a  reservoir  increased  by  placing  the  tile  deep. 

ground  water  between  the  tile  lines  will  be  lowered  quickly, 
and  at  no  time  will  it  be  much  higher  than  the  level  near  the 
tile  Unes. 

If  the  soil  be  retentive  and  resistant  to  the  flow  of  the 
water  to  the  tile  lines,  the  ground  water  may  come  very  near 
the  surface  at  a  rod  or  two  from  the  tile.  Thus  the  distance 
between  the  lines  depends  not  only  upon  the  depth  of  the  tile, 
but  also  upon  the  charae"^er  of  the  soil.  In  practice,  lines 
are  placed  50,  75,  100,  150,  and  200  feet  apart,  for  average 


DRAINAGE 


farm  crops,  depending  upon  the  conditions  and  the  thorough- 
ness of  drainage  desired. 

Systems  of  Tile  Lines.  There  are  several  general  systems 
of  arranging  tile  lines,  each 
of  which  is  adapted  to  cer- 
tain conditions.  A  descrip- 
tion of  the  various  systems 
follows. 


Nahjral  System 


Fig.     45.      The 


natural       system      of 
laying    out    tile    drains. 


The  natural  system  con- 
sists in  laying  tile  in  natural 
depressions,  or  it  is  an  at- 
tempt to  drain  the  soil 
needing  drainage  most. 

The  grouping  system  is 
used  where  sloughs  or  basins 
are  encountered  as  well  as 
dry  land  little  in  need  of 
drainage.  The  grouping  system  consists  of  mains  running 
into  the  sloughs  with  systems  of  drainage  to  thoroughly 

cover   the  area  of   the  soil 
needing  drainage. 

The  gridiron  system  is 
used  where  complete  drain- 
age is  desired,  as  on  very  flat 
fields.  The  laterals  are 
placed  parallel,  and  every 
part  of  the  entire  area  is 
within  a  certain  distance 
At  the 
end  of  the  parallel  laterals, 
mains  or  submains  of  larger  tile  are  laid  to  collect  the  dis- 
charge from  as  many  as  possible. 


Fig 


46.     The     grouping     system     of    frnm    the    tile    HnP 
laying    out    tile    drains.  ^^^"^    ^"*^    ^"^    ""^- 


10 


AGRICULTURAL  ENGINEERING 


Fig. 


Gridiron  System 

47.      The      gridiron      system      of 
laying    out    tile    drains. 


The  single  line  system  is 
one  in  which  the  outlet  for 
tile  lines  is  an  open  ditch. 
Tile  Hnes  in  this  case  are 
independent  of  one  another, 
and  each  must  have  its  own 
outlet. 

Large  Drainage  Systems. 
In  laying  out  a  large  drainage 
system  it  may  be  necessary 
to  use  several  of  the  various 
methods  or  systems  of  ar- 
rangement. There  are  no 
hard  and  fast  rules  for  any 
one    system,    though    short 


laterals  should  be  avoided 
whenever  possible,  because 
mains  will  drain  the  land  for 
some  distance  on  each  side, 
and  the  part  of  the  laterals 
extending  across  the  drained 
area  of  the  main  is  largely 
useless  as  far  as  adding  to 
the  drained  area  is  con- 
cerned. 

Straight  Tile  Lines.  Tile 
lines  should  be  as  straight  as 
possible,  and  when  curves 
are  required  they  should  not 
be  sharp.  In  addition  to  the 
fact  that  the  flow  of  water  is 
hindered  to  a  greater  extent 
in  tile  lines  with  sharp  turns 


c3 


Fig.    48.     The    single-line    system    of 
laying    out    tile    drains. 


DRAINAGE 


71 


than  in  straight  tile  hnes,  it  is  much  easier  to  lay  the  tile  in  a 
straight  ditch  than  in  a  curved  or  crooked  one.  The  system 
should  be  so  planned  that  all  lands  needing  drainage  should 
be  brought  under  the  influence  of  the  drains;  or,  in  other 
words,  the  system  should  insure  thorough  drainage. 

Staking  Out  the  Drains.  After  the  general  plan  has  been 
decided  upon,  the  next  step  is  the  staking  out  of  the  drains. 
To  do  this,  stations  are  located  at  distances  of  50  feet  apart 
on  the  Une  of  the  proposed  drain.  Two  stakes  are  required 
at  each  station.  One,  the  hub  or  grade  stake,  is  driven  into 
the  ground,  nearly  flush 
with  the  surface,  about 
one  foot  to  the  left  of 
where  the  center  of  the 
ditch  is  to  be  located,  as 
one  faces  the  outlet. 
Levels  are  taken  from  the 
top  of  these  grade  stakes 
and  the  cut  or  depth  of 
ditch  is  figured  down  from  Fig.  49. 
them.  These  grade  stakes 
may  be  of  any  convenient  material.  Inch  boards  split  into 
widths  of  about  2  inches  are  very  satisfactory.  The  length 
should  be  sufficient  to  insure  that  the  stake  will  be  solid 
in  the  ground.  Besides  the  grade  stake,  guide  stakes  of 
lath  or  other  light  material  are  required.  These  are  located 
near  the  grade  stakes  to  aid  in  finding  them,  and  are 
marked  with  numbers  to  identify  the  stations. 

All  stakes  should  be  left  in  place  until  the  work  is  finished 
and  accepted.  They  should  not  be  placed  long  before  the 
work  is  actually  to  begin,  since  they  are  quite  likely  to  be 
moved  out  of  place. 


'^-firade  Stake, 
or  Hub. 

Grade     stakes,     or 
guide  stakes. 


hubs,     and 


72  AGRICULTURAL  ENGINEERING 

QUESTIONS 

1.  What  is  the  discharge  end  of  a  tile  line  called?    The  upper  end? 

2.  What  is  a  lateral  drain?     A  submain?     A  main? 

3.  How  should  tile  drains  be  laid  on  slopes,  and  why  should  they 
be  so  laid? 

4.  How  deep  should  tile  drains  be  placed? 

5.  What  are  some  of  the  factors  to  be  considered  in  determining 
the  distance  between  drains? 

6.  Explain  the  following  systems  of  tile  drains:    The  natural 
system,  the  grouping  system,  the  gridiron  system,  the  single  line  system. 

7.  Why  should  short  laterals  be  avoided? 

8.  Why  is  a  straight  tile  line  desired? 

9.  What  two  kinds  of  stakes  are  required  in  staking  out  a  drainage 
system? 

10.  Describe  the  location  and  purpose  of  each. 


CHAPTER  XII 


LEVELING  AND  GRADING  TILE  DRAINS 

Taking  Levels.  After  the  drains  have  been  staked,  levels 
should  be  taken  with  an  instrument  on  the  grade  stake  at 
each  station  and  recorded  in  the  field  book.  This  is  the 
process  of  leveling  which  has  been  mentioned  in  a  previous 
chapter.  Notes  for  each  line,  be  it  main,  submain,  or  lateral, 
should  be  kept  under  an  appropriate  title  or  head,  and  all  the 
levels  should  refer  to 
a  common  datum.  If 
the  instrument  is  pro- 
vided with  a  compass, 
the  bearings  of  the 
line  should  be  record- 
ed on  the  right  hand 
side  of  the  note  book 
beside  the  level  notes. 
A  good  system  of 
notes  is  shown  in  the 
specimen  pages  from 
a  field  book  found  in 
Part  I. 

The  Grade.  The 
amount  of  slope  given 
to  tile  drains  is  called 
the  grade  and  is  stated  in  several  ways.  The  more  common 
way  is  to  give  the  change  in  elevation  of  the  drain  for 
every  hundred  feet  of  length.  It  is  also  stated  as  the 
percentage  the  change  of  elevation  is  of  the  length.    Thus 

73 


Fig.    50.     Taking    levels    in    making   a    survey. 


74 


AGRICULTURAL  ENGINEERING 


a  grade  of  .02  foot  per  hundred  feet  is  equal  to  .02  per  cent, 
etc.  Again,  the  grade  may  be  stated  in  inches  per  rod,  as, 
}/2  inch  per  rod  or  1  inch  per  rod.  It  is  customary  to  refer 
to  the  grade  as  the  ''fall.'*  Then  a  grade  of  .1  foot  per  100 
feet  is  called  a  ''fall''  of  .1  foot  per  hundred  feet,  and  a  grade 
of  1  inch  to  the  rod  has  a  "fall"  of  1  inch  to  the  rod.  The 
line  of  the  bottom  of  the  finished  ditch,  or  the  line  on  which 
the  tile  is  laid,  is  called  the  grade  line. 

Establishing  Grade  Lines.    After  the  elevations  of  the 
grade  stakes  have  been  obtained,  it  now  falls  to  the  lot  of  the 


5S 
58 
57 
56 
55 

^ 

= 

^ 

= 

= 

^ 

M 

= 

i 

d 

^ 

^ 

s 
^ 

M 

m 

1 

m 

^ 

M 

w^ 

m 

7^ 

m 

54 
53 
58 
5/ 
50 

P 

P 
^ 

m 

m 

m 

1 

^ 
s 

^ 

1 

§ 

^ 

g 

m 

^ 
^ 

^ 

1 

m 

M 

^ 

^ 

^ 

H 

H 

/O        II 


Pro-file   of  Main. 

Fig.  51.     A  profile  of  a  tile  drain. 


drainage  engineer  to  estabhsh  the  grade  for  the  tile  lines. 
There  are  two  methods  in  common  use  for  doing  this,  and 
they  will  be  explained  in  turn. 

Grade  Profile.  One  simple  and  also  very  satisfactory 
way  of  establishing  the  grade  for  the  tile  drain  is  to  plot 
the  system  on  profile  paper,  using  a  vertical  scale  to  show  the 
elevations  of  the  various  stations,  and  a  horizontal  scale, 
the  distance  between  stations.  The  vertical  scale  should 
show  differences  of  at  least  1-10  of  a  foot  in  elevation.    It 


DRAINAGE  75 

is  now  an  easy  matter  to  draw  trial  lines  upon  this  profile, 
locating  the  grade  of  the  tile  drain.  The  determination  of 
+he  grade  fine  usually  resolves  itself  into  the  problem  of 
locating  the  outlet  as  low  as  possible,  with  the  head  deep 
enough  to  secure  good  drainage  and  at  the  same  time  high 
enough  to  provide  sufficient  fall  for  the  line. 

Sometimes  a  thread  is  stretched  across  the  profile  as  an 
aid  in  deciding  the  proper  location.  After  the  grade  has 
been  properly  located,  the  elevation  of  the  grade  line  at  the 
various  stations  may  be  read  from  the  scale  of  the  profile. 

Second  Method.  If  the  elevation  of  the  grade  line  at  the 
various  stations  be  subtracted  from  the  elevation  of  the  sta- 
tion, the  cut,  which  is  the  depth  of  the  ditch  at  that  point, 
will  be  obtained.  It  is  convenient  to  adjust  the  grade  to 
even  hundredths  of  a  foot  per  100  feet,  as,  .02  or  .25  foot  per 
100  feet.  Two  additional  columns  should  now  be  utiUzed 
in  the  field  book.  One  should  be  marked  G.  L.,  which  is  to 
contain  the  elevations  of  the  grade  line  at  the  various  sta- 
tions; the  other  is  marked  "cuts,"  and  contains  the  depth 
of  the  ditch  below  the  top  of  the  grade  stakes  at  the  various 
stations.  It  is  possible  to  locate  the  grade  line  and  deter- 
mine all  cuts  at  various  stations  along  the  line,  without  the 
extra  work  in  connection  with  the  drawing  of  the  profile, 
but  the  profile  is  regarded  more  desirable. 

Unifonn  Grade  Desirable.  A  uniform  grade  should  be 
used  throughout  the  tile  fines  as  far  as  possible,  though  it  may 
not  be  economical  in  all  cases.  For  example,  if  the  tile  fine 
is  to  run  through  a  ridge  to  an  outlet,  the  grade  will  hkely  be 
established  by  placing  the  tile  at  the  minimum  depth  at  the 
head  end  of  the  tile  drain  to  reduce  the  cut  through  the  ridge 
as  much  as  possible  and  still  secure  a  practical  grade  for  the 
tile  fine  from  the  head  end  through  the  ridge.  After  passing 
through  the  ridge  the  grade  may  be  increased.     It  is  always 


76  AGRICULTURAL  ENGINEERING 

more  desirable  to  have  an  increase  than  a  decrease  in  the 
grade.  Where  the  grade  is  reduced  there  is  a  reduction 
in  the  velocity  of  flow  at  that  point,  which  permits  the  silt 
in  the  water  to  settle  in  the  tile. 

Joining  Laterals  to  Mains.  When  laterals  or  submains 
are  joined  to  another  drain,  it  is  advisable  to  have  a  sHght 
fall,  or  drop,  as  it  is  called,  into  the  main  at  the  end  of  the 
drain.  The  amount  of  drop  should  be  proportioned  to  the 
size  of  the  tile  into  which  the  drain  discharges.  Thus  for 
the  6-inch  main  the  drop  from  the  lateral  should  be  0.2  foot; 
for  an  8-inch,  0.3  foot;  for  a  10-inch,  0.4  foot;  and  for  a 
12-inch,  .5  or  3^2  fc)ot-  To  compute  the  elevation  of  the  start- 
ing point  for  each  drain  when  a  drop  is  to  be  provided,  the 
amount  of  the  drop  should  be  added  to  the  grade  elevation 
of  the  main  at  the  junction. 

Construction  Figures.  It  is  customary  for  the  engineers 
having  the  work  in  charge  to  indicate  upon  the  guide  stakes 
the  cut  at  the  various  stations.  For  convenience  of  those 
digging  ditches,  the  engineer  often  changes  the  decimal  of  the 
foot  to  inches.  It  is  also  customary  to  furnish  to  the  tile 
ditcher  a  tabulated  list  of  the  cuts  at  the  various  stations. 
Sometimes  this  is  furnished  and  the  marks  on  the  guide 
stakes  are  omitted. 

The  Final  Map.  After  the  drainage  system  has  been 
located  and  all  the  field  observations  made,  all  data  should 
be  reduced  to  a  permanent  map.  This  map  should  show  the 
/ocation  of  each  drain,  its  length,  head,  outlet  or  jimction 
with  another  line;  the  number  and  size  of  tile  required; 
location  of  all  surface  inlets,  silt  basins,  etc.  It  is  also  well 
to  record  the  grade  of  the  drain  from  point  to  point  and  the 
surface  elevations  and  cuts  at  representative  places.  No 
reputable  engineer  would  think  of  undertaking  the  design  of 


DRAINAGE 


77 


a  drainage  system  without  providing  the  owner  of  the  tract 
drained  with  such  a  map. 


-iT^ 


Fig.   52.     A  drainage  map. 


QUESTIONS 


1.  What  should  be  recorded  in  the  field  book  when  taking  levels 
for  a  tile  drain? 

2.  What  is  meant  by  the  "grade"  or  "fall,"  and  in  what  three 
ways  may  it  be  designated? 

3.  What  is  meant  by  the  grade  line? 

4.  Explain  two  methods  of  establishing  the  grade  line. 

5.  Why  is  a  uniform  grade  desirable? 

6.  Explain  how  laterals  should  be  joined  to  mains  or  submains. 

7.  What  construction  figures  should  be  placed  on  the  guide  stake? 

8.  Describe  the  construction  of  the  final  map. 


CHAPTER  XIII 
CAPACITY  OF  TILE  DRAINS 

Cause  of  Flow  in  Tile  Drains.  If  water  be  poured  into  an 
inclined  pipe  or  other  conduit,  it  will  flow  toward  the  lower 
end.  This  flow  is  produced  by  the  action  of  gravity.  The 
effect  of  gravity  may  be  observed  in  the  phenomena  of  f alHng 
bodies,  and  the  law  for  the  velocity  of  falhng  bodies  is  usual- 
ly expressed  by  the  formula: 


Y  =  y    2  gh 

where  V  is  equal  to  the  velocity  in  feet  per  second,  g  the  accelerating 
force  of  gravity,  and  h  the  distance  through  which  the  body  falls. 

Thus  a  freely  falling  body  starting  from  rest  will  have 
a  velocity  of  32.2  feet  per  second  at  the  end  of  the  first 
second.  At  the  end  of  the  second  second  the  velocity  will 
have  increased  to  64.4  feet  per  second,  and  there  will  be  an 
increase  in  velocity  each  second,  or  it  will  continue  to  accele- 
rate thereafter.  It  is  this  same  force  which  causes  the  flow 
of  water  in  tile  drains,  and  there  can  be  no  other  agent  to 
produce  the  flow.  In  the  tile  drains,  however,  there  are 
many  influences  to  interfere  with  the  acceleration  of  velocity, 
which  tend  to  make  the  velocity  uniform. 

Velocity  Formulas  for  Flow  of  Water.  There  have  been 
many  attempts  to  incorporate  into  a  formula  the  various 
factors  which  produce  and  retard  the  flow  in  tile  drains,  and 
many  such  formulas  have  been  proposed.  The  extent  to 
which  these  forces  retard  the  flow  of  water  in  pipes  cannot  be 
determined  accurately.    Some  of  these  forces  are  the  resist- 

78 


DRAINAGE  79 

ance  to  the  entrance  of  water  into  the?  pipe,  the  resistance  of 
the  walls  of  the  pipe  to  the  flow  of  the  water,  which  varies 
largely  with  the  roughness  of  the  inside  of  the  pipe,  the 
obstructions  at  joints  and  bends,  and  the  amount  of  sedi- 
ment deposited,  etc. 

Poncelet's  Formula.  One  of  the  more  generally  used 
formulas  which  have  been  proposed  for  the  flow  of  water  in 
tile  drains,  is  Poncelet's  formula.  The  usual  way  of  stating 
this  formula  is  as  follows : 

For  mean  velocity:  

In  which 

d  =  diameter  of  tile  in  feet. 

h  =  head,  or  diflference  in  elevation  between  outlet  and  upper  end, 

in  feet. 
I  =  length  of  drain  in  feet. 

Modification  of  Formula.  Under  varying  conditions 
which  are  encountered,  certain  modifications  of  the  formula 
will  be  found  necessary.  Thus  in  open  soil  where  the  water 
is  free  to  enter  the  tile  line,  it  is  recommended  by  Mr.  C.  G. 
Elliott,  formerly  Chief  of  the  Drainage  Investigations,  of  the 
United  States  Department  of  Agriculture,  that  3^  of  the 
depth  of  the  soil  over  the  drain  at  its  head  be  added  to  the 
quantity  dh,  making  the  formula  read : 


48       /  dh  -\-  }4k 
V         1  + 


54d 
In  which 

A;  =  the  depth  of  the  soil  over  the  drain  at  its  head. 

Mr.  Elliott  also  recommends  that  an  increase  in  the 
head  be  made  in  the  case  of  mains  which  have  a  com- 
paratively large  number  of  laterals,  on  account  of  the  drop 
of  these  laterals  into  the  main.    This  drop  in  the  submains 


80  AGRICULTURAL  ENGINEERING 

tends  to  increase  the  velocity  of  the  flow  in  the  mains. 
These  modifications  are  not  governed  by  any  law  and  they 
require  judgment  for  their  use. 

Run-off  from  Underdrained  Land.  In  addition  to  know- 
ing the  capacity  of  a  tile  drain,  the  engineer  must  know 
something  about  the  amount  of  water  which  must  be  taken 
care  of  from  the  given  area.  This  is  usually  spoken  of  as  the 
**  run-off,  "and  is  measured  by  the  depth  of  the  water  received 
if  spread  over  the  entire  area.  Thus  a  run-off  of  3^  inch  for 
an  acre  is  the  water  received  from  that  area  in  24  hours,  and 
is  sufficient  to  cover  the  acre  to  the  depth  of  3^  inch.  Many 
experiments  have  been  conducted  to  determine  the  run-off 
from  given  areas.  Sometimes  this  quantity  is  spoken  of  as 
the  "  Standard  Drainage  Coefficient,"  or  "  Standard." 
The  common  standard  used  for  small  areas  in  which  tile 
drainage  is  practiced  is  the  J^-inch  standard.  For  larger 
areas  the  standard  is  larger.  In  this  connection,  due  con- 
sideration should  be  made  for  surface  water  which  may  flow 
to  the  underdrained  land  from  adjoining  land.  This  may 
necessitate  the  doubling  of  the  capacity  of  the  tile  otherwise 
required. 

Application  of  Formula.  In  order  to  use  the  formula  for 
the  capacity  of  the  drain  tile,  it  is  necessary  to  know  the 
quantity  of  Water  discharged  per  second.  This  is  a  simple 
matter,  as  the  quantity  of  water  is  equal  to  the  area  of  the 
drain,  times  the  velocity.    Thus, 

Q  =  ay 
where  Q  is  equal  to  the  quantity  of  water  discharged  per  second,  a  is 
equal  to  the  area  in  square  feet  of  the  cross  section  of  tile,  and  v 
equals  the  velocity  in  feet  per  second. 

In  addition  to  this  it  is  necessary  to  know  the  number  of 
cubic  feet  per  second  that  is  equivalent  to  the  standard  used. 


DRAINAGE 


81 


This  may  be  computed  by  dividing  the  total  quantity  of 
water  on  an  acre,  for  a  certain  standard  or  depth,  by  the 
number  of  seconds  in  24  hours.  For  convenience,  however, 
the  following  table  is  included. 

Discharge  per  second  per  acre  for  different  depths  of  run-off. 


Common  fraction 

Depth  in  inches. 
Decimal 

Cu.  ft.  per  sec. 
per  acre 

1 

1.000 
.938 
.875 
.812 
.750 
.688 
.625 
.562 
.500 
.438 
.375 
.312 
.250 
.188 
.125 
.062 

.0420 

15-16 

.0394 

7-8 

.0367 

13-16 

.0341 

3-4              

.0315 

11-16 

.0289 

5-8 

.0262 

9-16 

.0230 

1-2 

.0210 

7-16 

.0184 

3-8 

.0157 

5-16                        

.0131 

1-4        

.0105 

3-16 

.0079 

1-8 

.0052 

1-16 

.0026 

In  applying  the  formula  it  is  customary  to  assume  a  cer- 
tain size  of  tile  and  then  make  the  computation  to  determine 
whether  or  not  the  tile  will  be  sufficient.  If  too  small, 
another  trial  may  be  made  with  a  larger  tile.  As  an  illus- 
tration, suppose  that  the  size  of  tile  necessary  to  drain  80 
acres  is  required,  when  the  line  is  1000  feet  long  and  is  laid 
to  a  grade  of  4-10  foot  per  100  feet,  assuming  the  drainage 
standard  or  coefficient  of  }4  inch. 

Referring  to  the  formula, 


48 


dh 

I  -{-  54d 


82  AGRICULTURAL  ENGINEERING 

Assume  that  an  8-inch  tile  will  be  required,  then: 

d  =  diameter  of  tile,   =  8  inches  or  %  foot. 

1000 
h  =  total  head  or  fall  =   .4  X =  4  ft. 

I   =  1000  feet. 
54d  =  54  X  %  =  36. 

«  =  area  of  cross  section  of  tile  =   H  X  3.1416  X  (HV   =.349 
square  feet. 

/   %  X  4 


V  =    48  -,/     rs  ^-t     ^  43       /  _^_  -|/~002574 

>^     1000  +  36  1/       3108  ^   "^      '^^^^^ 

=  2.40  feet  per  second. 
Q  =  cubic  feet  discharged  per  second,  and  equals  the  velocity  X 

area  of  cross  section  of  tile   =  2.4  X  -349   =   .8376. 

Referring  to  the  preceding  table  for  the  discharge  per 
second  per  acre  for  the  34-inch  standard,  we  find  .0105. 
Then  the  number  of  acres  drained  is 

.8376 
A  =      ^.^^    =  79.6,  or  practically  80. 
.0105 

If  the  answer  representing  the  discharge  per  second  pro- 
cured in  this  manner  should  be  too  great  or  too  small,  the 
calculation  would  be  made  for  smaller  or  larger  sizes  of  tile, 
as  the  case  may  be,  and  the  most  practical  tile  to  use  chosen. 

To  facilitate  the  use  of  the  formula,  a  table  may  be  made 
up  from  it,  showing  the  number  of  acres  which  may  be  drained 
with  various  sizes  of  tile  laid  to  various  grades.  The  follow- 
ing is  such  a  table,  from  Bulletin  68  of  the  Iowa  experiment 
station. 


DRAINAGE 


83 


00    u 
»^  S 


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i-H  ,-1  00  ^  (M 
COTfi  lOt^  00 


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pop  top 


84 


AGRICULTURAL  ENGINEERING 


Size  of  Laterals.  The  size  of  laterals  may  be  fixed  as 
soon  as  the  available  fall  is  obtained  by  the  taking  of  levels. 
In  general,  it  is  not  regarded  good  practice  to  use  small  tile  in 
laterals.  The  use  of  3-inch  tile  has  been  quite  generally  dis- 
continued in  favor  of  4-inch.  The  larger  tile  is  less  likely  to 
be  influenced  by  imperfect  construction,  and  the  difference 
in  cost  is  small.  There  is  a  minimum  grade  for  tile  lines 
less  than  which  it  is  not  practical  to  lay  tile.  If  the  soil  is 
free  from  sand  or  other  sediment-forming  elements,  the  grade 
may  be  quite  flat;  however,  if  the  soil  is  sandy  a  considerable 
slope  should  be  provided. 

On  account  of  the  resistance  to  flow  in  small  tile,  it  is  not 
best  to  make  lines  of  small  tile  longer  than  a  certain  length. 
The  following  table  gives  the  minimum  grade  and  maximum 
length  of  tile  lines  which  are  practical  with  various  sizes  of 
tile. 

Table  showing  minimum  grade  and  length  for  tiles  of  various  sizes.  * 


Size  of  tile  in  inches 

Minimum  grade  in 
feet  per   100  feet 

Limit    of   length    in 
feet 

3 

.10 
.06 
.06 
.06 
.06 
.05 
.05 
.05 
.04 
.04 

800 

4 

1600 

5 

2000 

6                                                  

2500 

7      .                        

2800 

8.   ..                    

3000 

9.   ..           

3500 

10 

4000 

11 

4500 

12 

5000 

♦From  Elliott's  "Engineering  for  Land  Drainage. 


PROBLEMS  FOR  PRACTICE  IN  THE  USE  OF  THE  FORMULA 

1.  Find  the  number  of  acres  that  may  be  properly  drained  by  a 
6-inch  tile  line  20  rods  long,  if  laid  with  a  grade  of  2-10  of  a  foot  per  100 
feet. 


DRAINAGE  85 

2.  What  size  tile  should  be  used  to  drain  properly  a  40-acre  tract, 
if  the  line  is  1200  feet  long  and  laid  with  a  grade  of  3-10  of  a  foot  per 
100  feet? 

(The  following  problems  are  taken  from  Bulletin  78  of  the  Iowa 
experiment  station,  involving  the  use  of  the  table.) 

3.  What  size  of  tile  laid  to  a  0.1  per  cent  grade  will  carry  the  under- 
drainage  of  160  acres  of  flat  land?    Ans.,  15  inches. 

4.  What  size  of  tile  laid  to  a  0.2  per  cent  grade  will  carry  the  under- 
drainage  of  240  acres,  ^  rolling?  Ans.,  80  acres  flat  land  plus  ^s  of 
160  acres  rolling  gives  133^  acres,  requiring  a  12-inch  tile. 

5.  What  size  of  tile  laid  to  0.3  per  cent  grade  will  be  required  to 
remove  both  ground  and  surface  water  from  a  pond  whose  watershed 
includes  40  acres?  Ans.,  10-in.  (Note. — Double  or  triple  the  area  for 
both  ground  and  surface  water.) 

QUESTIONS 

1.  What  causes  the  flow  of  water  in  tile  drains? 

2.  What  are  some  of  the  factors  which  influence  the  velocity  of  the 
flow  of  water  in  tile  drains? 

3.  Give  and  explain  Poncelet's  formula. 

4.  What  modifications  of  the  formula  may  be  made,  and  why? 

5.  What  is  meant  by  a  standard  drainage  coeflficient,  or  standard? 

6.  How  is  Poncelet's  formula  used? 

7.  How  may  the  capacity  or  discharge  of  a  tile  be  obtained  from 
the  velocity  of  flow? 

8.  Why  is  a  table  convenient  in  determining  the  size  of  tile? 

9.  What  is  meant  by  maximum  length  of  tile  lines? 


CHAPTER  XIV 
LAND  DRAINAGE 

Digging  the  Tile  Ditch.  After  the  survey  and  the  depths 
of  the  grade  hnes  at  all  stations  have  been  marked  plainly 
upon  the  guide  stakes,  it  then  becomes  the  duty  of  the  tiler 
to  dig  the  ditch,  or  trench,  accurately  to  grade,  and  to  place 
the  tile  closely  and  firmly  upon  the  bottom. 


Fig.  53.  Hand  tools  used  In  digging  tile  ditches.  Nos.  1 
and  2  are  square-end  tiling  spades,  3  and  4  are  open  or  skele- 
ton tile  spades,  5  is  a  tile  scoop  or  crumber,  6  is  a  round- 
point  shovel,  7  is  a  tile  hook,  and  8  a  soil  auger. 

Hand  Digging.  Tile  ditches  are  quite  generally  dug  by 
hand,  and  under  certain  conditions  it  is  the  only  practical 
method.    The  ditch  is  usually  dug  so  that  the  center  of  the 


DRAINAGE 


87 


top  of  the  ditch  will  be  about  one  foot  from  the  line  of  grade 
stakes.  A  straight  ditch  indicates  good  workmanship.  To 
secure  straightness,  a  small  rope  may  be  stretched  along  the 
line  of  the  ditch.  Curves  may  be  laid  out  by  using  the  rope 
as  a  radius  and  marking  numerous  points  along  the  Une  of 
curve  by  short  stakes. 

The  tools  required  for  digging  ditches  by  hand  are  not 
numerous.  A  ditching  spade  with  a  16-  to  20-inch  blade  is 
most  generally  used.  In  muck  soils,  an  open  three-tanged 
spade  will  be  more  satisfactory.  To  clean  out  the  loose  soil 
from  the  bottom  of  the  ditch,  a  long-handled  round-nosed 
shovel  is  the  most  efficient  tool.  To  take  out  the  last  bit  of 
soil  and  to  shave  the  bottom  of  the  ditch  down  to  an  even 
grade  to  receive  the  tile,  a  tiler's  scoop,  or  crumber,  is  neces- 
sary. 

Ditching  Machines.  Owing  to  the  large  amount  of  labor 
involved  in  digging  tile  ditches  by  hand,  attempts  have  been 
made  for  years  to  design  a  machine  which  would  do  the  work 
successfully.    At  the  present  time  there  are  some  machines 


Fig.   54.     A  tile  ditching  machine  at  work. 


88  AGRICULTURAL  ENGINEERINO 

that  do  very  creditable  and  economical  work.  Tile  ditching 
machines  have  either  a  power-driven  wheel  or  an  endless 
chain,  on  which  knives  and  buckets  are  attached  for  loosening 
the  soil  and  carrying  it  above  the  surface  where  it  may  be 
deposited  on  a  conveyor  and  carried  to  one  side  of  the  ditch. 
The  machine  must  be  so  constructed  that  the  cutting 
mechanism  can  be  easily  raised  or  lowered  and  equipped 
with  sights  or  gauges  which  indicate  clearly  the  depth  the 
machine  is  digging.     Steam  and  gasoHne  engines  are  used 


Fig.    55.     A    large    tile    ditching   machine    at   work. 

+0  furnish  the  power.  Traction  gearing  drives  the  whole 
machine  forward  at  the  proper  speed,  which,  in  favorable 
soil,  may  be  as  much  as  175  feet  per  hour  when  digging  four 
feet  deep  or  less. 

The  great  difficulty  in  the  past  has  been  to  design  a 
machine  which  would  dig  a  ditch  to  grade  in  soft  soil  having 
but  little  supporting  power.  This  has  been  overcome  to  a 
great  extent  by  providing  caterpillar  traction  wheels  or 


DRAINAGE 


89 


treads  which  provide  a  large  area  of  supporting  surface. 
These  machines  can  be  used  to  the  best  advantage  on  long 
hnes  of  tile  and  where  the  soil  is  reasonably  dry  and  free 
from  boulders.  In  no  case  should  a  machine  be  used  which 
does  not  permit  of  an  inspection  of  the  grade  and  of  the  tile 
as  it  is  laid. 

The  Guess  System  of  Laying  Tile.  At  the  present  time 
there  is  very  httle  tile  placed  in  the  ground  on  grade  Hnes 
made  simply  by  guess.  The  majority  of  such  systems  are 
failures,  and  mistakes  have  been  so  evident  where  this 
method  was  practiced  that  it  is  uncommon  now  to  see  a 
system  installed  without  a  survey. 

The  Water-Level  Method.  But  Httle  better  than  the 
guess  method  of  installing  drainage  systems,  is  the  water- 
level  method,  which  is  used  to  some  extent  today  and  is 
responsible  for  a  large  number  of  failures.  This  method  of 
laying  tile  is  used  where  there  is  some  water  in  the  ditch. 
Where  the  fall  is  slight,  water  can  not  be  depended  upon  to 
give  a  proper  grade.  The  ditch  is  sure  to  be  dug  below  the 
grade  at  certain  places,  giving  a  back  fall.  After  the  ditch 
has  been  dug  too  deep,  there  is  little  chance  of  correcting  the 
mistake  by  filling  in.  The  water-level  method  is  so  inaccu- 
rate that,  even  where 
the  fall  is  great  and 
there  is  little  danger 
of  creating  back  fall, 
the  grade  Hne  will  be 
so  irregular  that  the 
efficiency  of  the  tile 
will  be  much  reduced. 

Method  of  Grad- 
ing Ditches.  Two 
general    methods    of    ^'^-  ''■   "^^^  ""^dirchls?''  "'  ^"^'"^  '"' 


90 


AGRICULTURAL  ENGINEERING 


grading  ditches  are  in  vogue.  One  is  to  stretch  a  cord  or 
hne  above  the  surface  parallel  to  the  grade  line,  using  a 
measuring  stick  to  locate  the  grade.  This  is  generally  known 
as  the  *4ine  and  gauge  method."  The  other,  the  "target 
method,"  consists  in  locating  a  Hne  of  sights  or  targets  above 
the  ditch,  parallel  to  the  required  bottom,  and  the  depths  at 

all  points  are  gauged  by- 
sighting  over  these  sights 
and  using  a  measuring 
stick  to  determine  the 
proper  depth. 

When  the  line  is  used 
it  must  first  be  decided 
how  far  above  the  bottom 
of  the  ditch  to  place  it, 
and  a  measuring  rod  of 
this  length  provided. 
Five  or  seven  feet  are 
convenient  distances  for 
the  usual  depth  of  dig- 
ging. The  line  may  be 
stretched  directly  over  the 
ditch  or  to  one  side.  The 
first  instance  requires  that 
a  yoke  be  constructed 
over  the  ditch,  while  the 
latter  requires  only  a 
single  standard  or  stake. 
Some  tilers  object  to  the  hne  stretched  over  the  ditch, 
as  it  is  more  or  less  in  the  way,  but  there  is  no  doubt  that 
more  accurate  measurements  can  be  made  when  the  line  is 
so  placed.  If  the  Hne  be  stretched  at  one  side  of  the  ditch, 
a  measuring  stick  with  a  bracket  must  be  used.    To  obtain 


Fig.    57. 


The   target    method   of   grading 
tile   ditches. 


DRAINAGE  91 

greater  accuracy,  a  level-tube  is  sometimes  placed  on  the 
horizontal  arm  of  the  bracket.  The  height  of  the  line  above 
the  grade  stake  at  each  station  is  obtained  by  subtracting 
the  cut  from  the  distance  the  line  is  placed  above  the  grade 
line.  Thus,  if  7  feet  be  selected  as  the  length  of  the  measur- 
ing stick,  and  the  cut  at  a  certain  station  be  3  feet  5  inches, 
then  the  Une  should  be  placed  7  feet  less  3  feet  5  inches, 
or  3  feet  7  inches  above  it.  If  this  operation  be  performed 
at  all  stations,  it  will  be  seen  that  the  line  will  be  parallel 
to  the  bottom  of  the  ditch  and  7  feet  above  it.  A  fishline  or 
a  fine  wire  makes  an  excellent  Hne  to  use  for  this  purpose, 
as  it  may  be  stretched  very  tight,  overcoming  the  sag  to  a 
large  extent.  Some  experienced  tilers  prefer  the  ''target 
method,"  as  it  is  more  convenient.  It  is,  however,  more  pro- 
ductive of  errors. 

Selecting  Tile.  Great  care  must  be  used  in  selecting 
drain  tile.  Farm  drainage  is  too  expensive  for  one  to  take 
serious  risks  with  tile  of  questionable  durabiUty.  At  the 
present  time  there  is  much  discussion  in  regard  to  the  rela- 
tive merits  of  clay  and  cement  tile.  Attention  has  been 
called  repeatedly  to  instances  where  both  kinds  have  failed. 
Clay  tile  has  the  advantage  in  that  it  has  been  in  use  a  much 
longer  time  than  cement  tile,  and  a  good  clay  tile  is  as  per- 
manent as  any  material  that  can  be  secured.  Careful  speci- 
fications for  tile  and  methods  for  testing  the  same  have  not 
as  yet  been  prepared  or  devised. 

Clay  tile  should  be  well  burned  and  of  uniform  shape  and 
color.  They  should  be  straight,  with  square  ends,  and  when 
two  are  held  in  the  hands  and  struck  together  they  should 
give  a  good  sharp  ring.  Large  lumps  of  chalk  or  lime  in  the 
clay  must  be  guarded  against.  Inferior  tile  are  those  of  light 
color,,  porous  and  laminated.  These  are  quite  sure  to  become 
disintegrated  when  placed  in  the  soil. 


92  AGRICULTURAL  ENGINEERING 

Cement  tile  are  very  satisfactory  when  properly  made 
and  are  of  recognized  quality.  No  attempt  should  be  made 
to  make  the  tile  porous,  but  as  dense  a  mixture  of  cement  as 
it  is  possible  to  secure  should  be  used.  Where  good  coarse 
sand  is  used,  a  mixture  of  1  part  cement  to  2}4  parts  of  sand 
has  been  used  by  the  best  manufacturers.  A  mixture  con- 
taining less  cement  will  no  doubt  make  good  tile.  Large 
cement  tile  should  be  reinforced  with  steel. 


Fig,    58.     Drain  tile.     Those  at  the  left  are  of  cement  and  those  at  the 
right  are  clay. 

In  installing  a  drainage  system,  a  careful  inspection  of  the 
tile  should  be  made.  All  inferior  tile  which  are  soft,  porous, 
cracked,  or  overburned  until  of  reduced  size,  should  be 
discarded. 

Laying  Tile.  Great  care  should  be  taken  in  laying  the 
tile.  Small  tile  should  be  laid  with  the  tile  hook  (See  Fig. 
59),  but  there  is  little  doubt  that  the  tile  is  laid  more  accu- 
rately when  laid  by  hand.  Each  length  should  be  turned  as 
it  is  laid  to  secure  the  best  fit.  When  a  tile  hook  is  used  on 
tile  which  are  sHghtly  curved,  the  bend  of  the  tile  is  quite  sure 
to  be  up,  leaving  a  larger  crack  at  the  top  of  the  tile  rather 


DRAINAGE 


9a 


than  at  the  bottom,  which  is  undesirable.  Tile  should  be 
fitted  together  so  that 
there  are  no  cracks  over 
3^  inch  wide.  Small  holes 
at  the  joints  may  be  cov- 
ered by  broken  pieces  of 
tile. 

In  digging  the  ditch 
and  laying  the  tile,  the 
work  should  always  begin 
at  the  outlet.  The  tile 
should  be  laid  as  fast  as 
the  ditch  is  dug,  to  pre- 
vent the  destruction  of 
the  ditch  by  rain.  This 
would  happen  if  the  water 
should  be  allowed  to  flow 
down  the  unprotected 
ditch.  In  most  soils,  the 
open    ditches    are    quite 

likely     to     cave     m     if    left    Fig.    59.     Laying  tlle   with   the   tile  hook, 

open  during  rain  storms. 

Laterals  should  be  joined  to  a  main  by  '' Y''  connections 

furnished  by  the  tile  manufacturers.    The  cheapness  of  these 

connections  does  not  justify 
the  work  of  cutting  tile  to 
form  a  connection.  Laterals 
should  enter  the  main  at  as 
sharp  an  angle  as  convenient. 
When  the  connection  is  made 

method ^  of    ?^In*ng^^a^te?Ii*"(frai'nr^to     at    right  anglcS,    the    floW   of 
mains.     From  Ohio  Exten.  Bui.  47.  ^^^  ^^^^^    ^^^^    ^^^    ktcrals 

has  a  tendency  to  check  the  flow  of  the  water  in  the  mains. 


94  AGRICULTURAL  ENGINEERING 

In  laying  through  quicksand,  time  should  be  given  for 
the  water  to  drain  out  and  allow  the  sand  to  become  as  firm 
as  possible.  This  is  rather  a  slow  process  at  times,  but  it  is 
the  only  method  to  follow  in  watery  quicksand.  To  prevent 
the  sand  from  flowing  into  the  open  end  of  the  tile,  a  screen 
of  hay  or  grass  may  be  used.  If  there  are  bad  pockets,  it 
may  be  necessary  to  lay  the  tile  upon  boards  to  keep  them 
to  grade. 

Inspection.  Before  the  tile  are  covered  the  work  should 
be  thoroughly  inspected  to  see  that  the  tile  are  laid  to  grade, 
and  that  the  openings  between  the  tile  are  not  too  large.  In 
inspecting  the  grade,  the  level  may  be  set  over  the  Hne  of  tile 
and  the  hne  of  sight  set  to  the  same  slope  as  the  grade  line. 
The  reading  of  the  rod  held  upon  the  top  of  the  tile  should  be 
the  same  at  all  points,  so  long  as  the  slope  of  the  grade  line 
does  not  change.  After  inspection,  the  tile  should  be 
"blinded  in"  by  cutting  enough  dirt  from  the  side  of  the 
ditch  to  cover  it  to  the  depth  of  two  or  three  inches.  This 
earth  from  the  side  of  the  ditch  is  more  porous  than  that  from 
the  surface,  and  permits  the  water  to  enter  the  tile  more 
readily.  The  shoveling  and  spading  of  the  soil  have  a  ten- 
dency to  puddle  it  and  make  it  water-tight.  After  bhnding, 
the  ditch  may  be  filled. 

QUESTIONS 

1.  What  is  the  work  of  the  tiler? 

2.  Explain  in  a  general  way  the  digging  of  tile  ditches  by  hand. 

3.  Name  and  describe  the  tools  used  in  tile  ditching. 

4.  Where  may  tile  ditching  machines  be  used  to  advantage? 

6.  How  much  ditch  may  be  dug  with  a  machine  in  an  hour  under 
favorable  conditions? 

6.  Why  should  not  tile  be  laid  by  guess? 

7.  Explain  the  "water  level"  method  of  installing  drains. 

8.  Describe  the  line  method  of  digging  ditches  to  grade. 


DRAINAGE  95 

9.  What  relation  does  the  line  of  targets  or  sights  in  the  target 
method  of  digging  ditches  to  grade,  bear  to  the  grade  Une? 

10.  What  points  should  be  observed  in  selecting  drain  tile? 

11.  Explain  in  detail  how  the  targets  are  located.     The  line. 

12.  Describe  the  use  of  the  tile  hook. 

13.  How  should  tile  be  fitted? 

14.  How  may  tile  be  laid  through  quicksand? 

15.  What  is  meant  by  "blinding"  the  tile? 

16.  Why  should  tile  Unes  be  inspected? 

17.  Describe  the  work  of  inspection  of  tile  draina. 


CHAPTER  XV 
CONSTRUCTION  OF  TILE  DRAINS 

Filling  by  Hand.  After  the  tile  are  laid  and  blinded  in, 
as  little  hand  labor  as  possible  should  be  used  in  filUng  the 
ditches.  The  usual  price  for  the  work  of  filhng  ditches  by 
hand  is  ten  cents  per  rod,  while  the  same  work  will  cost  one 
to  two  cents  per  rod  where  horses  and  implements  are  used. 
Of  course  there  are  places  near  and  under  fences  or  embank- 
ments where  the  ditches  must  be  filled  by  hand. 


Fig.    61.     Filling  the  ditch  with  a  plow. 

Filling  with  the  Plow.  One  of  the  most  convenient  and 
satisfactory  methods  of  filhng  a  tile  ditch  is  to  plow  it  full. 
To  do  this  successfully,  an  ordinary  stirring  plow  may  be 
used,  one  horse  being  hitched  to  each  end  of  a  long  double- 

96 


DRAINAGE  97 

tree  which  will  permit  one  horse  to  walk  on  each  side  of  the 
ditch.  The  soil  and  waste  banks  are  plowed  toward  and 
into  the  ditch  until  it  is  entirely  filled.  It  is  best  that  one 
man  drive  the  team  while  another  hold  the  plow.  Three 
horses  may  be  used  upon  a  twelve-foot  evener,  two  horses 
hitched  to  one  end  and  one  to  the  other.  In  this  case  the 
plow  is  attached  four  feet  from  the  end  to  which  the  team  is 
hitched.  The  plow  is  not  well  adapted  for  filling  ditches  dug 
in  meadow  land. 

Filling  with  a  V  Drag.  A  V  drag  is  a  useful  and  quick 
means  of  filling  ditches.  The  wings  of  the  drag  should  be 
wide  enough  in  front  to  reach  from  the  outside  of  one  bank 
of  excavated  earth  to  the  outside  of  the  other,  and  should  be 
brought  to  within  a  few  feet  of  each  other  at  the  rear. 

Filling  with  Road  Machines.  A  scraping  road  grader  may 
also  be  used  to  fill  tile  ditches.  The  blade  may  be  set  at  such 
an  angle  that  the  waste  bank  is  scraped  over  into  the  ditch. 
Like  the  road  drag,  the  road  machine  will  do  good  work  if  the 
ground  is  not  too  wet. 

Another  common  method  is  to  fill  the  ditch  with  a  sUp 


Fig.   G2.     Filling  the  ditch  with  a  road  grader. 


98 


AGRICULTURAL  ENGINEERING 


scraper  or  other  form  of  handled  scraper.  A  team  is  hitched 
to  the  scraper  by  a  chain  so  as  to  pull  directly  across  the 
ditch.  The  scraper  is  placed  behind  the  waste  bank,  and  the 
team  stepping  ahead  pulls  a  scraper  load  of  earth  into  the 
ditch.  The  team  is  then  backed  and  the  scraper  pulled  back 
by  hand.  The  latter  operation  furnishes  the  greatest  objec- 
tion to  this  system,  for  it  is  very  heavy  work. 

Outlet  Protection.     All  tile  outlets  should  be  protected 
in  such  a  manner  that  the  earth  will  not  be  washed  away 

from  the  end  tile 
and  cause  them  to 
be  displaced.  The 
cheapest  form  of 
outlet  is  made  by 
preparing  a  wooden 
box  into  which  the 
last  few  lengths  of 
tile  may  be  placed. 
This  is  not  a  very 
satisfactory  form  of 
protection.  The  bet- 
ter plan  is  to  build  a 

Fig,    63,     A    good   outlet    protection    for    a    tile  bulkhcad  of  maSOUrV 
drain.      It    is    desirable,    however,    that    grating 

or  bars  be  placed  across  the  outlet  to  keep  out  and  an  apron  UPOU 
small  animals.  ^  ^ 

which  the  water 
may  spill  without  washing  away  the  soil.  The  latter 
may  not  be  needed,  or  a  few  stones  will  generally  suffice. 
Concrete  makes  a  splendid  bulkhead.  A  six-  to  ten-inch 
wall  where  only  two  or  four  feet  of  earth  is  to  be  held 
back  will  be  found  sufficient.  This  wall  should  extend  well 
below  the  tile  to  prevent  undermining.  The  last  few  tile 
should  be  glazed  sewer  tile,  as  they  will  resist  freezing  and 
thawing  better  than  common  drain  tile.    Iron  rods  or  netting 


DRAINAGE 


99 


should  be  placed  across  the  outlet  to  prevent  the  entrance  of 
small  animals  which  might,  by  dying  in  the  tile,  become  an 
obstruction. 

Catch  Basins,  or  Surface  Inlets.  Where  there  is  sure  to 
be  considerable  surface  flow,  it  is  best  that  this  be  taken  into 
the  tile  as  soon  as  possible.  The  catch  basin  is  simply  a 
grated  inlet  leading  directly  to  the  tile.  The  basin  is  usually 
built  deeper  than  the  tile  to  allow  dirt,  which  might  be 
washed  in,  to  settle  and  not  be  carried  into  the  tile  with  the 
water.  This  sediment  should  be  cleaned  out  from  time  to 
time. 

A  concrete  box,  33^  feet  across  and  vnih  4-inch  walls, 
makes  a  very  satisfactory 
catch  basin.  The  box 
should  extend  2  feet  below 
the  Hne  of  tile  and  should 
have  a  removable  cover. 
Large  sewer  pipes  with 
side  connections  can  be 
used  conveniently  for  this 
purpose. 

Silt  Basins.  Silt  basins 
have  been  recommended 
for  tile  lines  where  the 
grade  is  reduced,  and  are 

designed  to  provide  a  receptacle  to  catch  the  silt  that  is 
likely  to  settle  at  that  point.  They  are  constructed  with 
removable  covers  through  which  the  sediment  may  be  re- 
moved from  time  to  time.  There  is  little  doubt  that  these 
devices  are  very  harmful  in  checking  the  flow  of  water  in  the 
tile,  and  it  has  been  the  experience  of  the  author  that  these 
basins  are  never  given  attention  when  they  require  it. 


Fig.     64.     A    silt    basin. 


100 


AGRICULTURAL  ENGINEERING 


Trouble  with  Roots  of  Trees.  Tile  drains  laid  near 
aquatic,  or  water-loving,  trees,  are  sometimes  partially,  if 
not  entirely,  obstructed  by  roots  of  these  trees.  The  willow 
and  water  elm  are  among  those  that  give  the  most  trouble  in 
this  respect.  Fruit  trees  give  very  little  trouble,  and  drains 
may  be  laid  in  orchards  with  impunity. 

If  a  drain  must  pass  within  30  or  40  feet  of  any  of  the 
trees  that  are  aquatic  by  nature,  the  trees  should  be  cut  down 


Fig.    65. 


A    tile    drain    which    became    completely    obstructed    by    roots 
from  a  willow  tree. 


and  killed,  or  sewer  pipes  with  cemented  joints  should  be 
used  near  the  trees,  which  will  prevent  the  roots  from  getting 
into  the  drains. 

Drainage  Wells,  or  Sinks.  Wells  are  occasionally  used 
as  outlets  for  tile  drains.  It  is  known  that  about  as  much 
water  may  be  discharged  into  a  well  as  may  be  pumped  from 
it.    An  investigation  of  the  success  of  wells  as  drainage  out- 


DRAINAGE 


101 


lets  in  Iowa  reveals  that  in  certain  localities  wells  are  emi- 
nently successful;  in  others,  they  are  failures  after  a  very 
short  time.  The  successful  wells  seem  to  be  those  that 
penetrate  crevices  in  the  rock  stratum  below  the  surface. 
These  wells  seem  less  likely  to  become  clogged  with  the  fine 
silt  carried  into  the  well  by  drainage  waters.  It  is  under- 
stood that  these  wells  are  to  be  used  for  no  other  purpose 
than  as  drainage  outlets. 

Cost  of  Drain  Tile.  To  those  unfamiliar  with  tile  drain- 
age, it  is  thought  that  the  following  schedule  of  tile  prices 
at  the  factory  will  be  useful.  It  is  to  be  remembered  that 
prices  must  necessarily  vary  with  factories,  and  freight  in 
many  cases  is  a  considerable  item. 

Cost  of  drain  tile  at  the  factory. 


Size  of  tile  in  inches 

Weight.     Lba. 

Cost  per  1000 

4    .                        

7 
9 
11 
17 
26 
35 

$  16 

5 

20 

6 

28 

8 

45 

10 

80 

12 

100 

Schedule  of  Prices  for  Digging  Ditches.  The  follow- 
ing schedule  prices  have  been  in  quite  general  use  through- 
out Iowa  during  the  year  1911. 


Cost  of  digging  tile  ditches. 

Size 
in 

of  tile 
inches 

Price  per  rd. 

3    ft.    deep    or 

less 

Extra  per  rd. 

for  each  inch 

of  depth  over 

3  ft. 

Extra  per  rd. 

for  each  inch 

of  depth  over 

6  ft. 

4  5,  and  6 

$.44 
.50 
.621^ 
.75 

S.OIM 
.01^ 
.02 
.03 

$.03 

7  and  8 

.033^ 
.04 

9  and  10 

12 

.05 

.102  AGRICULTURAL  ENGINEERING 

QUESTIONS 

1.  Why  is  it  advisable  to  use  little  hand  labor  in  filling  the  ditches? 

2.  How  may  the  plow  be  used  in  filling  ditches? 

3.  Describe  the  use  of  the  V  drag  and  road  grader  in  filling  ditches. 

4.  Why  should  the  outlet  of  a  tile  drain  be  protected? 

5.  Describe  the  construction  of  an  outlet  protection. 

6.  What  is  the  purpose  of  a  catch  basin? 

7.  Describe  the  construction  of  a  catch  basin. 

8.  Where  is  a  silt  basin  used  and  what  is  its  purpose? 

9.  How  may  tile  drains  be  protected  from  the  roots  of  trees? 

10.  To  what  extent  may  a  well  be  used  as  an  outlet  for  tile  drains? 

11.  Compare  the  prices  of  drain  tile  furnished  in  the  text   with 
those  of  your  town  or  city. 

12.  What  are  the  usual  prices  charged  for  tile  ditching? 


CHAPTER  XVI 


OPEN  DITCHES 

Drainage  of  Large  Areas.  Where  large  areas  are  to  be 
drained,  it  may  not  be  practical  to  install  tile  of  sufficient 
size  to  care  for  the  drainage  water  or  run-off.  Thus  in  the 
large  drainage  systems  it  is  to  be  expected  that  open  ditches, 
as  distinguished  from  covered  or  tile  lines,  will  be  used  to 
supplement  the  tile. 

Construction  of  Open  Ditches.  In  the  construction  of 
open  ditches,  not  only 
the  size  must  be  con- 
sidered, but  also  the 
form  of  the  ditch. 
The  size  of  the  ditch 
will  depend  upon  the 
capacity  of  ditches 
dug  to  various  grades 
and  upon  the  area 
and  character  of  the 
catchment  basin.  The  ng.  ce. 
capacity  of  open  ditch- 
es will  be  discussed  later.  Care  should  be  used  in  construct- 
ing the  banks  of  the  ditch  so  that  the  ditch  will  remain 
open  and  not  become  filled  by  the  caving  of  the  banks. 

In  certain  soils  a  slope  of  1  foot  horizontal  to  1  foot  ver- 
tical for  the  sides  of  the  ditch  may  be  maintained;  and  in 
other  cases,  as  in  the  case  of  loam  soil,  the  slope  must  be  1}^ 
to  1,  or  even  less.  In  digging  a  ditch  it  is  often  not  possible 
to  secure  the  desired  slope  in  the  beginning,  but  the  ditch 

103 


A  noatins  dredge  for  digging  open 
ditches. 


104  AGRICULTURAL  ENGINEERING 

is  made  deep  enough  so  that  as  it  caves  in  it  will  still  be  of 
sufficient  size.  The  heap  of  excavated  earth  from  a  ditch  is 
called  the  waste  hank.  The  space  between  the  waste  bank 
and  the  edge  of  the  ditch  is  called  the  herm.  Waste  banks 
present  an  ugly  appearance  and  are  an  objectionable  feature 
of  open  ditches,  unless  the  earth  is  used  to  fill  in  low  places. 

Cost  of  Open  Ditches.  Small  open  ditches  are  made 
with  the  plow  or  scraper.  These  are  usually  undesirable,  as 
they  do  not  furnish  a  good  outlet  for  the  ground  water. 
Large  open  ditches  are  generally  built  by  contractors  who 
are  provided  with  ditching  or  dredging  machines.  In  many 
cases  these  are  floating  dredges  which  begin  at  the  head  of  the 
ditch  and  dig  toward  the  outlet.  There  are  other  types  of 
ditching  machines,  which  operate  on  tracks  laid  on  each  side 
of  the  proposed  ditch.  These  large  machines  remove  the 
earth  from  the  ditch  at  a  very  reasonable  cost,  varjang  from 
5  to  15  cents  per  cubic  yard. 

Disadvantages  of  Open  Ditches.  There  are  many  dis- 
advantages of  open  ditches.  Small  ditches  do  not  furnish 
good  outlets  for  the  ground  water  because  they  cannot  be 
kept  open  to  sufficient  depth.  It  is  to  be  noted  that  an  open 
ditch  will  not  drain  below  the  surface  of  the  water  in  the 
ditch.  Again,  open  ditches  interfere  seriously  with  the  culti- 
vation of  the  land,  and  are  very  unsightly.  They  occupy 
so  much  land  as  to  make  their  upkeep  expensive.  Further- 
more, more  plant  food  is  carried  off  by  an  open  ditch  than  by 
a  tile  drain.  If  the  water  must  pass  down  through  the  soil 
to  a  tile  drain,  more  or  less  of  the  plant  food  will  be  left  in 
the  soil. 

Capacity  of  the  Open  Ditch.  As  in  the  case  of  tile  drains, 
there  have  been  many  attempts  to  prepare  a  formula  which 
would  enable  one  to  compute  the  capacity  of  open  ditches. 
There  are  a  good  many  factors  which  influence  the  flow  of 


DRAINAGE 


105 


water  in  ditches.  One  of  the  most  important  of  these  is  the 
cleanness  of  the  ditch.  A  very  Httle  rubbish,  if  allowed  to 
accumulate  in  an  open  ditch,  will  decrease  its  capacity  materi- 
ally. Grass  and  weeds  may  grow  in  an  open  ditch  to  such  an 
extent  as  to  reduce  the  capacity  of  the  ditch  to  less  than  half. 


Fig.    67.     An    excavator    for   dlgrgin^   open    ditches,    which   is    carried    on 
tracks   laid  at  each  side  of  the   ditch. 

The  following  tables  computed  by  Kutter's  formula  will 
be  useful  in  this  connection.*    These  tables  are  taken  from 


♦Kutter's  formula  for  the  velocity  of  flow  in  open  ditches  is  as  follows* 
1.811      ,      ,,  „.      .       .00281 


+    41.65    + 


1    +   Al.65    + 


.00281 


)x7 


v 


in  which  v   =  velocity  of  flow  in  feet  per  second. 

i     =  sine  of  the  inclination  of  the  slope,  or  the  fall  of  the  water  surface  in  a 

given  distance  divided  by  that  distance, 
r    =  area  of  the  cross  section  in  square  feet  divided  by  the  wet  perimeter 

in  lineal  feet, 
n    =  coeflficient  of  friction    for  dififerent  sizes  of  canals  and  with  different 

degrees  of  roughness. 


106 


AGRICULTURAL  ENGINEERING 


Bulletin  78  of  the  Iowa  experiment  station.  A  coefficient  of 
roughness  of  .03  has  been  used  and  they  are  for  ditches  having 
the  sides  with  slopes  of  one  foot  horizontal  to  one  foot  vertical . 
The  ditches  are  not  to  run  more  than  8-10  full,  where  the 
capacity  is  mentioned.  Above  the  upper  heavy  lines  in 
the  table  the  %  inch  standard  of  water  for  24  hours  is  used; 
between  heavy  lines  the  }/2  inch  standard;  and  below  the 
lower  heavy  lines  the  3^  inch  standard. 

Number  of  acres  drained  by  open  ditches. 
Depth  of  water  5  feet.  Depth  of  ditch  at  least  6J^  feet. 


Grades 

Average  width  of  water 

Per 

cent 

Ft. 
per 
mile 

6 

feet 

8 
feet 

10 
feet 

15 

feet 

20 
feet 

so 

feet 

60 
feet 

0.02 

1.0 

980 

1470 

1900 

5000 

7150 

23800 

43800 

0.04 

2.1 

1390 

2090 

2800 

7200 

20400 

33500 

62500 

0.06 
0.08 

3.2 

4.2 

1710 
1980 

2560 
2980 

5100 
6100 

17600 
20400 

24700 
30000 

40800 
48800 

75500 
88000 

0.10 

5.3 

2220 

5010 

7600 

23400 

83400 

54500 

98000 

0.15 

7.8 

2720 

6300 

17100 

28700 

40500 

66700 

120000 

0.20 

10.6 

4820 

7300 

19500 

33000 

47000 

77000 

139000 

0.25 
0.30 
0.40 

13.2 
15.8 
21.1 

5370 
5900 
6830 

16300 
17900 
20600 

21900 
23900 
27700 

37500 
40700 
47000 

53000 
57000 
67000 

86000 
94000 

155000 
170000 

0.50 

26.4 

7600 

23000 

31000 

0.60 
0.70 
0.80 
0.90 

31.7 
37.0 
42.2 
47.5 

16700 
18100 
19000 
20500 

25200 
27300 

33900 

• 

DRAINAGE 


107 


Number  of  acres  drained  by  open  ditches. 

Depth  of  water  7  feet.  Depth  of  ditch  at  least  9  feet. 


Grade 


Average  width  of  water 


Per 

Feet 

8 

10 

15 

20 

30 

60 

cent 

per  mile 

feet 

feet 

feet 

feet 

feet 

feet 

0.02 

1.0 

2300 

4700 

16600 

28000 

48000 

88500 

0.04 

2.1 

4850 

6740 

23400 

35400 

58000 

106000 

0.06 

3.2 

5920 

17000 

29600 

43400 

72000 

129000 

0.08 

4.2 

6940 

19100 

34200 

50000 

83000 

150000 

0.10 

5.3 

7720 

21800 

38400 

56000 

92600 

167000 

0.15 

7.8 

19400 

27000 

47200 

68500 

112000 

202000 

0.20 

10.6 

22400 

31300 

54200 

78700 

130000 

235000 

0.25 

13.2 

25000 

34800 

60500 

88000 

146000 

0.30 

15.8 

27400 

38200 

66200 

96500 

0.40 

21.1 

31700 

44100 

0.50 

26.4 

35400 

QUESTIONS 

1.  When  may  it  be  necessary  to  use  open  ditches  as  drains? 

2.  What  are  some  of  the  disadvantages  of  open  ditches  or  drains? 

3.  What  slope  is  usually  given  the  sides  of  open  ditches? 

4.  What  is  the  "waste  bank"?    The  "berm"? 

5.  How  much  does  the  digging  of  open  ditches  cost  per  cubic  yard? 

6.  What  factors  influence  the  capacity  of  open  ditches? 

7.  WTiat  formula  is  generally  used  in  computing  the  capacity  of 
open  ditches? 


CHAPTER  XVII 
DRAINAGE  DISTRICTS 

Definitions.  The  drainage  district  is  an  organization  of 
the  owners  of  land  for  the  purpose  of  constructing  and  main- 
taining a  drainage  system  where  the  cost  is  to  be  shared  in 
proportion  to  the  benefits  derived.  Such  an  organization  is 
necessary  where  an  individual  cannot  drain  without  involving 
the  use  of  the  land  of  his  neighbors.  A  drainage  district 
may  include  at  least  three  classes  of  land:  First,  all  of  the 
adjacent  land  which  in  itself  may  not  be  in  immediate  need 
of  drainage;  second,  land  in  partial  need  of  drainage;  and 
third,  worthless  land  which  would  be  reclaimed  by  drainage. 

In  every  drainage  district  there  are  two  kinds  of  work: 
First  the  co-operative  work,  such  as  the  construction  of  large 
drains  or  ditches;  second,  the  individual  work  required  by 
land  owners  in  supplying  laterals  or  submains. 

Drainage  Laws.  The  organization  of  drainage  districts 
is  a  matter  which  involves  many  details  and  which  is  subject 
to  special  laws  in  most  states.  These  special  drainage  laws 
usually  cover  the  essential  steps  of  procedure;  and  the 
features  of  the  organization  of  a  drainage  district  are  as 
follows :  First,  the  right  of  the  property  owners  to  petition 
for  the  construction  of  drains  alleged  to  be  of  public  benefit. 
Second,  provision  for  making  and  collecting  assessments,  as 
well  as  the  appraisement  and  payment  of  damages.  Third, 
the  estabUshment  of  the  perpetual  right  of  land  owners  to 
the  use  of  the  drains  which  are  to  be  constructed  in  the 
district.  Fourth,  the  authority  to  obtain  money  by  incur- 
ring debt  or  selling  bonds,  under  the  proper  legal  regulations. 

108 


DRAINAGE  109 

Survey  and  Report.  After  a  petition  has  been  made  for 
the  formation  of  a  drainage  district,  the  law  places  the  matter 
of  a  survey  and  report  of  the  district  in  the  hands  of  a  board 
or  an  officer  of  the  law  to  order  the  survey  and  report  by  an 
engineer.  This  report  should  be  comprehensive  in  extent, 
and  should  furnish  sufficient  data  concerning  the  district  to 
enable  the  board  or  the  officer  of  the  law  to  determine  whether 
or  not  it  will  be  of  benefit  to  the  district  as  a  whole. 

The  report  in  this  case  should  include  an  estimate  of  the 
cost  of  the  work  to  be  performed  in  the  district,  covering  the 
actual  cost  of  the  construction  of  the  drains  and  the  neces- 
sary work  in  connection  therewith,  such  as  construction  of 
bridges,  etc.  It  should  include  an  estimate  of  damages  to 
all  property  owners  which  may  be  incurred  from  the  con- 
struction of  the  drains;  also  estimates  of  the  cost  of  the 
engineering,  of  fees  of  the  commissioners,  and  of  all  legal 
expenses  arising  from  the  suits  which  may  be  carried  to  court. 

Damages.  Provision  is  usually  made  for  a  commission 
of  disinterested  men  to  appraise  the  damages  which  may  come 
to  the  individual  property  owners  through  the  construction 
of  the  drainage  work.  Sometimes  this  board  of  commis- 
sioners is  also  called  upon  to  levy  the  assessment  of  benefits. 

Assessment  of  Benefits.  It  is  usually  provided  by  law 
that  the  total  cost  of  the  drainage  district  shall  be  assessed 
according  to  the  benefits  derived.  These  benefits  may  be 
either  specific  or  general ;  specific  in  that  the  value  of  the  land 
may  be  increased,  and  general  in  that  the  health  of  the  com- 
munity is  improved  by  the  drainage  district. 

There  are  many  things  involved  in  levying  an  assessment, 
and  these  are  more  or  less  subject  to  state  laws.  Copies  of 
drainage  laws  may  be  obtained  by  applying  to  the  secretary 
of  state  in  any  state,  and  these  laws  may  be  made  the  subject 
of  an  interesting  study. 


110  AGRICULTURAL  ENGINEERING 

QUESTIONS 

1.  What  is  a  drainage  district? 

2.  When  is  a  drainage  district  necessary? 

3.  What  three  classes  of  land  may  it  include? 

4.  What  two  kinds  of  drainage  work  does  it  include? 

5.  What  are  the  four  essential  features  of  laws  relating  to  drainage 
districts? 

6.  What  is  required  in  the  survey  and  report  of  a  drainage  district? 

7.  What  does  the  cost  of  a  drainage  district  include? 

8.  Describe  the  assessment  of  damages  in  a  drainage  district. 

9.  What  is  meant  by  assessment  of  benefits? 

REFERENCE  TEXTS 

Engineering  for  Land  Drainage,  by  C.  G.  ElUott. 
Practical  Farm  Drainage,  by  C.  G.  Elliott. 
Land  Drainage,  by  Manley  Miles. 
Irrigation  and  Drainage,  by  F.  H.  King. 
Notes  on  Drainage,  by  E.  R.  Jones. 
Bulletins  of  U.  S.  Department  of  Agriculture. 
Bulletins  of  state  experiment  stations. 


PART  THREE— IRRIGATION 


CHAPTER  XVIII 
fflSTORY,  EXTENT,  AND  PURPOSE  OF  IRRIGATION 

Control  of  Soil  Moisture.  Attention  has  been  called  to 
the  importance  of  having  the  soil  contain  the  proper  amount 
of  moisture  to  furnish  the  best  conditions  for  the  growth  of 
crops.  Plants  require  that  the  soil  contain  a  sufficient  amount 
of  moisture,  not  only  to  dissolve  the  plant  food,  but  also  to 
enable  them  to  absorb  and  assimilate  it.  Much  of  the  plant 
food  in  the  soil  is  made  available  through  the  action  of  micro-' 
scopic  organisms.  The  vitality  of  these  organisms  depends 
largely  upon  an  adequate  supply  of  moisture.  As  has  been 
explained,  drainage  is  for  the  purpose  of  relieving  the  soil  of 
a  surplus  moisture;  on  the  other  hand  there  may  be  in  certain 
localities  at  times  and  in  other  locaUties  at  all  times  a  defi- 
ciency of  moisture  from  natural  sources.  Irrigation  is  simply 
a  process  of  supplying  water  to  the  soil  by  artificial  means, 
either  to  make  it  possible  to  grow  crops  or  to  increase  pro- 
duction. 

Irrigation,  then,  is  the  reverse  of  drainage;  and  although 
this  be  true,  it  is  to  be  noted  that  irrigation  practice  has 
many  features  in  common  with  drainage.  The  management 
of  water  is  much  the  same,  regardless  of  whether  it  is  to  be 
removed  from  the  soil  as  in  the  case  of  drainage  or  supplied 
to  the  soil  as  in  the  case  of  irrigation. 

The  importance  of  irrigation  may  be  made  clear  by  calling 
attention  to  the  fact  that  many  crops,  like  potatoes  and  corn, 

111 


112  AGRICULTURAL  ENGINEERING 

during  the  part  of  the  growing  season  when  the  tubers  or 
ears  are  forming,  require  a  large  amount  of  plant  food  and 
moisture.  At  this  time  the  plants  have  a  wonderful  root 
development,  absorbing  a  great  amount  of  soil  moisture;  and 
if  maximum  yields  are  to  be  secured,  sufficient  moisture  must 
be  supplied. 

History  of  Irrigation.  The  practice  of  irrigation  runs 
back  even  before  the  time  history  began  to  be  written. 
There  is  evidence  that  irrigation  was  practiced  along  the 
Nile  and  the  Euphrates  rivers  more  than  2000  years  B.  c. 
There  were  also  large  irrigation  works  in  Baluchistan  and 
India  before  the  Christian  era.  Many  of  these  ancient  works 
have  been  abandoned,  yet  not  a  few  have  been  maintained 
and  are  still  in  use.  In  the  Western  Hemisphere,  irrigation 
was  practiced  at  a  very  early  date  in  Peru,  in  South  America, 
and  by  the  Aztec  civiUzation  in  North  America.  The 
remains  of  ancient  irrigation  works  are  to  be  found  in  parts 
of  Arizona  and  New  Mexico. 

Settlers  in  the  vicinity  of  San  Antonio,  Texas,  began  to 
practice  irrigation  as  early  as  1715.  When  the  Mormons 
settled  in  the  Salt  Lake  Valley  in  1847,  they  soon  began  to 
give  attention  to  the  matter  of  irrigation,  and  much  credit 
for  the  development  of  irrigation  methods  should  be  given 
to  these  pioneers.  As  early  as  1870,  a  colony  known  as  the 
Greely  Union  Colony  was  established  in  northern  Colorado, 
and  began  the  construction  of  works  for  irrigation.  Since 
that  time  irrigation  has  grown  by  bounds  in  the  United 
States. 

Dr.  Elwood  Meade,  former  Chief  of  Irrigation  Investiga- 
tions, U.  S.  Department  of  Agriculture,  has  estimated  that 
the  area  now  under  irrigation  in  countries  from  which  it  is 
possible  to  secure  rehable  statistics,  aggregates  85,000,000 
acres.    Taking  into  account  countries  which  do  not  have 


IRRIGATION  113 

statistics,  he  estimates  that  the  total  irrigated  area  is  not  far 
from  100,000,000  acres,  or  about  the  area  of  the  state  of 
California.    This  area  is  being  rapidly  increased. 

Professor  F.  H.  King  states  in  his  book,  ''Irrigation  and 
Drainage,"  published  in  1907,  that  the  area  irrigated  in 
India  was  about  25,000,000  acres,  in  Egypt  about  6,000,000 
acres,  in  Italy  3,700,000  acres,  in  Spain  500,000  acres,  and 
in  France  400,000  acres. 

The  following  data  are  taken  from  the  prehminary  report 
of  the  United  States  Census  of  1910.  These  figures  are  for 
the  arid  states  of  the  United  States,  and  do  not  include  rice 
irrigation. 

Total  acreage  irrigated  in  1909 13,739,499  acres 

Area  irrigation  enterprises  were  capable  of  irrigating 

in  1910 19,355,711     " 

Area  included  in  irrigation  projects 31,112,110    " 

Total  cost  of  irrigation  systems  constructed $304,699,450 

Average  cost  per  acre  (based  upon  construction  to  July  1, 
1910,  and  acreage  enterprises  were  capable  of  supply- 
ing in  1910) $15.76 

Average  annual  cost  per  acre  of  maintenance  and  opera- 
tion   $1.07 

PURPOSES  OF  IRRIGATION 

To  Supply  Moisture.  By  far  the  most  important  pur- 
pose of  irrigation  is  to  supply  moisture  when  needed  for  plant 
growth,  as  has  already  been  explained.  In  some  localities 
crops  cannot  be  grown  at  all  without  irrigation,  and  in  others 
irrigation  is  practiced  in  order  to  supplement  rainfall  and 
increase  the  crop. 

To  Control  Temperature.  In  some  localities  irrigation  is 
practiced  chiefly  to  control  the  temperature.  Cranberry 
marshes  are  often  flooded  with  water  to  protect  the  crop  from 
frost.    In  other  localities  the  soil  is  warmed  in  winter  by 


114  AGRICULTURAL  ENGINEERING 

causing  a  thin  sheet  of  water  to  flow  over  it,  and  the  same 
process  may  have  a  cooHng  effect  in  summer.  This  kind  of 
irrigation  is  practiced  in  Italy  where  a  supply  of  warm  water 
is  obtainable. 

To  Kill  Weeds.  In  rice  fields  the  surface  of  the  ground 
is  flooded  in  some  instances  largely  for  the  purpose  of  killing 
weeds,  thus  reducing  the  labor  of  cultivation.  Such  a 
system  also  protects  the  crop  from  the  ravages  of  birds  and 
insects. 

To  Supply  Fertility.  Irrigation  may  be  practiced  in  some 
locahties  in  order  to  supply  additional  fertility  to  the  soil. 
Some  irrigation  water  carries  a  large  amount  of  sediment 
which  is  very  rich  in  plant  food.  The  water  may  also  con- 
tain soluble  plant  food,  as  phosphoric  acid,  potash,  and 
nitrogen.  The  fertihty  of  the  land  along  the  Nile,  in  Egypt, 
which  has  been  irrigated  for  ages,  is  maintained  largely  by 
the  addition  of  fertility  through  the  irrigation  waters. 

It  is  true  that  some  water  supplies  cannot  be  used  for 
irrigation,  because  they  contain  poisons  injurious  to  plants. 
This  is  often  true  of  the  water  of  rivers  into  which  the  refuse 
from  smelters  and  certain  kinds  of  factories  is  discharged. 

Disposal  of  Sewage.  In  many  instances  the  disposal 
of  sewage  waters  from  cities  has  not  only  been  facilitated, 
but  also  made  a  matter  of  profit,  through  irrigation.  Sewage 
water,  when  applied  to  the  soil  is  quickly  purified  and  made 
harmless.    Sewage  water  is  usually  very  rich  in  plant  food. 

QUESTIONS 

1.  Define  irrigation. 

2.  Why  is  an  adequate  supply  of  moisture  in  the  soil  important? 

3.  How  long  has  irrigation  been  practiced? 

4.  How  much  land  in  the  world  is  now  irrigated?     In  U.  S.? 

5.  What  is  the  main  purpose  of  irrigation? 

6.  Name  and  describe  four  other  purposes  of  irrigation. 


CHAPTER  XIX 
IRRIGATION  CULTURE 

The  Amount  of  Water  Required  for  Crops.  As  explained 
in  the  part  of  the  text  devoted  to  drainage,  nature  does  not 
in  all  eases  supply  the  amount  of  water  which  will  produce  the 
maximum  growth  of  plants.  In  this  connection  the  question 
of  the  amount  of  water  which,  when  properly  applied,  will 
produce  a  paying  yield  of  crops,  is  one  of  vast  importance 
to  those  interested  in  irrigation.  In  most  instances  irriga- 
tion water  is  expensive,  and  for  the  sake  of  economy  no  more 
water  should  be  used  than  necessary.  The  question,  how- 
ever, is  very  complex,  and  cannot  be  treated  otherwise  than 
very  briefly  in  this  text. 

The  water  which  comes  to  the  soil  leaves  it  in  three  dif- 
ferent ways:  First,  a  portion  of  it  is  transpired  through 
plants;  second,  a  portion  evaporates  from  the  surface  of  the 
soil;  third,  a  certain  amount  of  the  water  flows  away  over  the 
surface  or  as  underground  drainage.  Plants  grow  by  using 
water,  as  described  under  the  first  head.  The  other  two 
ways  in  which  the  water  leaves  the  soil  may  be  considered 
losses,  and  should  be  reduced  to  the  minimum. 

There  are  many  conditions  which  modify  the  amount  of 
water  required  for  irrigation.  These  may  be  enumerated  as 
follows. 

The  Nature  of  the  Crop  Grown.  Some  crops  transpire 
more  than  others,  because  they  have  more  foliage  to  give 
off  the  moisture.  The  root  growth  of  the  plant  is  a  factor  in 
determining  the  amount  of  moisture  used,  as  the  roots  of  some 

115 


116  AGRICULTURAL  ENGINEERING 

plants  strike  deep  and  are  thus  able  to  draw  moisture  from 
a  larger  volume  of  the  soil. 

Character  of  the  Soil.  The  amount  of  water  required  is 
dependent  largely  upon  the  character  of  the  soil;  thus  the 
soil  may  be  so  open  or  porous  as  to  permit  a  rather  large  loss 
of  moisture  by  seepage.  The  character  of  the  soil  influences 
to  a  rather  large  extent  the  effectiveness  of  the  soil  mulch 
which  conserves  the  moisture  in  the  soil,  which  is  to  be 
described  later. 

Character  of  the  Subsoil.  The  character  of  the  subsoil 
is  a  factor  in  determining  the  amount  of  water  required  by 
the  plant,  for  an  open  subsoil  will  be  the  means  of  a  great  loss 
of  moisture  by  percolation  downward. 

Effect  of  Cultivation.  Cultivation  for  maintaining  a  soil 
mulch  will  influence  to  a  large  extent  the  amount  of  moisture 
required  for  most  satisfactory  plant  growth.  In  dry-farming 
locahties,  as  well  as  elsewhere,  moisture  is  conserved  by  keep- 
ing a  dust  mulch,  or  fine  layer  of  soil,  over  the  surface.  Much 
of  the  moisture  in  the  soil  available  for  the  growth  of  plants 
may  be  retained  in  this  way  from  one  wet  season  through  a 
dry  season.  After  a  rain  or  an  appHcation  of  irrigating  water, 
it  is  customary  to  cultivate  the  soil  as  soon  as  practical  in 
order  to  form  this  mulch. 

Closeness  of  Planting.  A  dense,  heavy  crop  that  shades 
the  ground  will  check  the  loss  of  moisture  by  evaporation. 
Thus  it  is  customary  to  irrigate  grain  crops  most  thoroughly 
at  the  time  when  they  are  heavy  enough  to  shade  the  ground. 

Character  of  Rainfall.  The  character  of  the  rainfall  is  an 
important  factor  in  fixing  the  duty  of  water;  one  heavy  rain 
which  penetrates  the  soil  to  a  considerable  depth  is  more  use- 
ful than  several  fight  rains  which  are  quickly  evaporated. 
Thus  localities  which  have  a  wet  season  are  often  able  to 


IRRIGATION 


117 


grow  crops,  even  though  the  actual  rainfall  is  quite  small, 
inasmuch  as  it  may  be  stored  in  the  soil  and  conserved  by 
cultivation  for  use  during  the  dry  season. 

Frequency  of  Appljdng  Water.  In  Uke  manner  the  fre- 
quency of  applying  irrigation  water  is  a  factor  which  deter- 
mines the  duty  of  water.  One  good  thorough  irrigation, 
under  most  conditions,  is  preferable  to  several  Hght  appli- 
cations. 

The  Amount  of  Water  Used  in  Irrigation.  It  is  to  be 
expected  that  the  student  is  anxious  to  know  how  much 
water  must  be  applied  to  the  soil  to  supply  the  plants  where 
the  rainfall  is  not  sufficient,  or  where  the  rainfall  is  too  slight 
to  be  considered.  The  amount  of  water  is  usually  designated 
in  inches  or  feet.  This  means  that  the  water  applied  is 
sufficient  to  cover  the  entire  surface  to  a  depth  indicated  in 
inches  or  feet  as  occasion  may  require.  The  actual  amount 
of  water  varies  largely,  as  may  be  expected. 

Mr.  H.  M.Wilson,  in  "Manual  of  Irrigation  Engineering," 
gives  the  following  table  setting  forth  the  amount  of  water 
used  in  irrigation  in  different  countries. 

Amounts  of  water  used  in  irrigation  in  various  countries. 


Name  of  country 


No.  of  acres  per 
second  foot  * 


No.  of  inches  per 
10  days 


Northern  India 

Italy 

Colorado 

Utah 

Montana 

Wyoming 

Idaho 

New  Mexico 

Southern  Arizona. . . 
San  Joaquin  Valley. 
Southern  California . 


60  to  150 

65  to    70 

80  to  120 

60  to  120 

80  to  100 

70  to    90 

60  to    80 

60  to    80 

100  to  150 

100  to  150 

150  to  300 


3.967 

3.661 

2.975 

3.967 

2.975 

3.4 

3.967 

3.967 

2.38 

2.38 

1.587 


to  1.587 
to  3.4 
to  1.983 
to  1.983 
to  2.38 
to  2.644 
to  2.975 
to  2.975 
to  1.587 
to  1.587 
to    .793 


*See  Chapter  XXI  for  definition  of  this  unit. 


118 


AGRICULTURAL  ENGINEERING 


Dr.  Elwood  Meade  furnishes  the  following  table  as  the 
duty  of  water  for  different  crops  in  the  United  States : 

Depth  of  water  used  for  different  crops  and  the  irrigation  season  for  each. 


Crop 

Depth  of  Irrigation. 
Feet 

Irrigating  season 

Potatoes 

3.94 
3.39 
2.76 
2.68 
2.15 
1.73 
1.49 
1.40 

May  17,  to  Sept.  15 
April  1,  to  Sept.  22 
April  15,  to  Sept.  2 
April  1,  to  July  26 
July  13,  to  Aug.  17 
May  22,  to  Aug.  20 
June  12,  to  Aug.  1 
July  24,  to  July  29 

Alfalfa 

Orchard 

Wheat 

SufiT&ir  bGets   . 

Oats 

Barley 

Corn 

Crqps  Grown  by  Irrigation.  Most  farm  crops  can  be 
grown  successfully  by  irrigation  methods,  and  no  attempt 
will  be  made  here  to  discuss  all.  It  is  desirable,  however, 
to  discuss  some  of  the  chief  crops  grown  in  this  way. 

Grain.  One  of  the  principal  crops  grown  by  irrigation  is 
grain,  and  it  is  one  which  adapts  itself  well  to  irrigation 
methods.  When  land  is  brought  under  irrigation,  grain  is 
usually  one  of  the  first  crops  to  be  grown.  There  are  several 
reasons  for  this.  Cereals  are  food  crops  and  are  always  in 
demand.  They  do  especially  well  on  virgin  soil  and  they 
require  the  least  output  in  preparing  the  land.  Furthermore, 
grain  is  an  excellent  crop  to  prepare  the  land  for  other  crops 
to  follow  later. 

In  most  locahties  there  is  enough  moisture  in  the  soil  to 
start  the  grain  at  the  beginning  of  the  growing  season,  and  the 
number  of  times  that  irrigation  water  must  be  apphed  will 
depend  upon  the  factors  which  have  been  described.  In 
some  locahties  along  the  Pacific  coast  and  in  New  Mexico 
and  Arizona  it  may  be  necessary  to  apply  irrigation  water 
during  the  winter  or  nongrowing  season.     In  other  localities 


IRRIGATION  119 

where  there  is  sufficient  rainfall  to  start  the  grain,  irrigation 
is  not  practiced  until  the  grain  is  six  or  eight  inches  high.  It 
is  generally  considered  better,  however,  if  it  is  found  neces- 
sary to  irrigate  near  the  time  of  planting,  to  irrigate  before 
planting  rather  than  after. 

On  light  soils  with  free  underdrainage  it  may  not  be 
possible  to  retain  the  moisture  through  the  winter  season, 
in  which  case  irrigation  should  be  practiced  near  the  time  of 
planting.  It  is  to  be  noted,  however,  that  in  some  localities 
it  may  be  advisable  to  irrigate  after  planting,  in  order  that 
the  time  of  planting  may  not  be  delayed.  The  principal 
danger  in  irrigation  after  planting  hes  in  the  formation  of 
crusts.  When  the  crust  forms  it  must  be  either  softened 
with  a  subsequent  irrigation  or  broken  up  mechanically  by 
means  of  special  rollers  or  peg-tooth  harrows. 

It  is  considered  best  not  to  furnish  so  much  water  as  to 
grow  a  large  straw  crop.  Heavy  straw  crops  make  a  large 
demand  upon  the  soil  moisture,  and  are  not  essential  for 
large  crops  of  grain.  Grain  is  also  likely  to  be  of  more  value 
when  grown  on  straw  that  does  not  have  a  rank  growth.  It 
is  customary,  then,  to  dispense  with  as  much  irrigation  during 
the  growing  season  as  is  possible  without  lowering  the 
vitality  of  the  grain. 

In  some  locaUties  only  one  irrigation  is  necessary,  and  this 
is  given  at  the  time  when  grain  is  in  the  milk  stage.  It 
seems  quite  important  that  the  grain  ^be  supphed  with 
abundant  moisture  at  this  time.  In  other  localities  where  it 
is  quite  dry  and  where  the  conditions  of  soil  and  climate 
require  it,  two  or  more  irrigations  may  be  given. 

Alfalfa.  One  of  the  great  crops  of  the  irrigated  land  in 
the  United  States  is  alfalfa.  Like  grain,  if  an  ample  supply 
of  moisture  is  given  to  the  soil  before  the  seed  is  sown, 
there  will  be  httle  need  of  another  early  irrigation.     If  the 


120  AGRICULTURAL  ENGINEERING 

land  be  irrigated  following  the  sowing  of  the  seed,  the  same 
difficulties  will  be  encountered  as  in  the  case  of  grain. 

The  first  thorough  irrigation  is  usually  given  after  the 
crop  shades  the  ground.  After  the  first  crop  is  harvested, 
each  subsequent  crop  is  irrigated,  as  a  rule,  but  once.  Prac- 
tice as  regards  the  time  of  this  irrigation  varies  in  different 
localities.  Sometimes  the  water  is  applied  perhaps  a  week 
or  ten  days  before  the  time  of  cutting.  The  intervening 
time  is  necessary  in  order  that  the  soil  may  be  dried  out  suffi- 
ciently to  enable  the  mowing  machine  and  hay  tools  to 
operate  successfully.  In  other  localities  it  is  practical  to  cut 
the  crop  first  and  apply  the  water  afterwards. 

Potatoes.  Favorable  conditions  for  the  growth  of 
potatoes  are  to  be  found  generally  throughout  the  irrigated 
regions  in  the  United  States.  In  the  irrigation  of  potatoes, 
care  should  be  used  not  to  irrigate  oftener  than  is  necessary, 
as  a  low  temperature  is  produced  which  is  unfavorable  to  the 
growth  of  potatoes.  For  this  reason  the  minimum  of  water 
is  supplied,  until  the  time  for  the  formation  of  the  tubers. 
Potatoes  seem  to  thrive  best  when  the  irrigations  are  few 
but  thorough,  and  cultivation  is  practiced  to  retain  the 
moisture  between  irrigations. 

Sugar  Beets.  About  two  thirds  of  the  beet  sugar 
produced  in  the  United  States  comes  from  the  irrigated 
sections,  and  it  is  one  of  the  crops  which  can  be  very  success- 
fully grown  by  irrigation  methods.  Sugar  beets  are  grown 
over  a  rather  broad  range  of  soils,  and  irrigation  practices 
vary  widely  with  different  localities.  Where  the  soil  is  open 
and  the  winter  season  especially  dry,  winter  irrigation  is 
practiced;  but  where  there  is  sufficient  amount  of  moisture 
in  the  soil  to  start  the  crop,  irrigation  may  be  omitted 
entirely  before  the  time  of  seeding.  The  first  irrigation  is 
generally  delayed  as  long  as  possible,  or  as  long  as  the  beets 


IRRIGATION  121 

are  making  a  steady  growth.  Two  or  four  applications  are 
usually  made  during  the  growing  season.  The  time  of  these 
applications  is  determined  by  the  condition  of  the  plants. 
Just  as  soon  as  they  begin  to  suffer  for  want  of  water  it  is 
applied.  The  last  application  usually  comes  within  four  or 
six  weeks  before  the  harvest.  This  final  irrigation  is  one 
that  requires  considerable  skill  in  order  that  it  may  be  given 
at  the  proper  time;  for  if  beets  are  allowed  to  mature  too 
soon  the  sugar  content  will  be  low. 

Orchard  Irrigation.  Orchard  irrigation  is  a  general 
practice  in  certain  regions.  This  no  doubt  is  due  to  the  fact 
that  irrigation  represents  intensive  agriculture  and  is  well 
suited  to  the  growing  of  fruits,  both  large  and  small,  as  the 
value  of  the  crop  per  acre  is  generally  large.  It  is  customary 
in  irrigation  practice  for  orchards,  to  keep  the  moisture  con- 
tent of  the  soil  high  enough  to  insure  favorable  conditions  for 
the  growth  of  the  trees  at  all  times.  Methods  vary  more  in 
orchard  irrigation  than  in  any  other.  In  some  localities 
the  practice  of  thoroughly  wetting  the  soil  and  conserving 
the  moisture  by  cultivation  prevails.  Sometimes  pipes  or 
similar  conduits  are  used  to  give  a  constant  supply  of  water 
to  the  soil.  Although  the  last  system  is  not  practiced  to 
any  extent,  it  is  common  to  find  it  in  some  localities. 

QUESTIONS 

1 .  In  what  three  ways  does  soil  moisture  leave  the  soil? 

2.  In  what  kind  of  soil  will  moisture  losses  by  seepage  be  greatest? 

3.  Discuss  four  factors  that  influence  the  amount  of  water  required 
in  irrigation. 

4.  Why  is  thorough  wetting  better  than  many  light  applications? 
6.  How  much  water  is  required  for  the  common  crops  in  the  United 

States,  as  estimated  by  Dr.  Elwood  Meade? 

6.  Explain  the  general  methods  followed  in  irrigating  grain, 
alfalfa,  potatoes,  sugar  beets,  and  orchards. 


CHAPTER  XX 
SUPPLYING  WATER  FOR  IRRIGATION 

Canals.  One  of  the  principal  ways  of  obtaining  irri- 
gation water  is  by  the  diversion  of  natural  streams  by  means 
of  canals.  The  design  and  construction  of  the  canals  vary 
widely  with  localities;  but  in  general  the  principles  involved 
are  the  same  as  those  involved  in  the  design  of  open  ditches 
or  drainage  canals,  which  have  been  considered  in  a  previous 
chapter.  It  is  customary  to  compute  the  capacity  of  irri- 
gation canals  by  Kutter's  formula,  which  is  given  on  page  105. 

Diversion  canals  lead  the  water  of  a  river  away  from  its 
natural  course  to  the  upper  side  of  the  area  to  be  irrigated. 
The  essential  engineering  features  of  a  canal  consist  in 
securing  such  a  grade  as  to  insure  a  sufficient  velocity  of 


'""..■■■-,-' 

WK/^^ 

^^j^^^^i"- 

B 

Fig.  68.  Riverside  Canal  in  Colorado  before  the  water  was  turned 
In  for  the  first  time.  This  canal  where  shown  is  18  feet  wide  at  the 
bottom. 


122 


IRRIGATION  123 

flow  to  get  the  necessary  capacity  and  to  keep  the  canal 
clean,  or,  as  usually  stated,  cause  it  to  ''scour." 

The  construction  of  a  canal  is  an  important  matter.  In 
the  early  stages  of  irrigation  practice  in  the  United  States, 
most  canals  were  made  with  earth  embankment,  but  the 
increase  in  the  value  of  irrigation  water  has  led  to  the  intro- 
duction of  methods  to  prevent  waste  from  the  canals  by 
seepage.  It  is  estimated  that  47  per  cent  of  the  irrigation 
water  now  used  in  the  United  States  is  wasted  in  this  way, 
and  in  some  cases  the  losses  run  as  high  as  85  per  cent. 

Some  irrigation  canals  are  ranked  among  the  world's 
greatest  engineering  achievements.  The  Cavour  Canal  in 
Europe  cost  $20,000,000;  its  waterway  is  66  feet  wide  and  12 
feet  deep,  and  it  crosses  the  drainage  Unes  of  several  rivers. 
It  passes  under  the  Sesia  River  in  a  masonry  siphon  820  feet 
long.  There  are  some  large  canals  in  Egypt  and  India. 
Among  them  may  be  mentioned  the  Chenab  Canal,  which  is 
250  feet  wide  at  the  bottom  and  carries  11  feet  of  water. 
The  main  canal  is  400  miles  long,  and  has  1200  miles  of 
tributary  canals.  It  cost  $10,000,000,  and  it  is  said  to  irri- 
gate 2,645,000  acres  of  land.  There  are  no  canals  in  the 
United  States  that  will  compare  with  it.  The  Bear  River 
canal  in  Utah  cost  $1,000,000  and  waters  approximately 
100,000  acres.  The  Modesto-Turlock  canal  system  of 
California  is  designed  to  water  275,000  acres,  and  cost  about 
$3,000,000. 

Reservoirs.  Reservoirs,  either  natural  or  artificial, 
obtained  by  the  damming  or  storage  of  water  in  natural 
watercourses,  are  often  made  the  source  of  supply  of  water 
for  irrigation  purposes,  inasmuch  as  water  which  would 
ordinarily  be  wasted  is  held  in  storage  until  needed.  In 
some  localities  reservoirs  are  quite  necessary,  as  streams 
furnish  the  minimum  amount  of  water  during  the  time  when 


124 


AGRICULTURAL  ENGINEERING 


irrigation  water  is  needed  most.     Under  other  conditions, 
reservoirs  are  little  needed. 

Forests  are  natural  reservoirs  to  the  extent  that  they  hold 
the  snow  in  mountainous  countries  and  prevent  a  rapid  sur- 
face run-off  of  the  water.  In  some  localities  the  irrigation 
water  comes  from  glaciers,  which  have  been  found  to  regulate 
the  supply  in  a  satisfactory  and  natural  way.  Thus  the 
maximum  amount  of  water  is  furnished  when  the  weather  is 


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69.     View    of   the    Roosevelt    Dam    on    the    Salt   River, 
(Bui.    235,   Office   of  Experiment  Stations.) 


hottest  and  the  requirements  are  the  greatest.  Sometimes 
reservoirs  are  placed  at  the  end  of  the  canal  in  order  that  the 
supply  of  water  may  be  on  hand  near  the  land  to  be  irrigated, 
so  that,  if  a  sudden  demand  for  water  is  made  which  will 
exceed  the  capacity  of  the  canal,  the  water  from  the  reservoir 
may  be  released. 

Reservoirs  have  been  used  in  connection  with  irrigation 
since  very  early  times.     In  India  nearly  ten  million  acres  of 


IRRIGATION  125 

land  are  now  irrigated  from  reservoirs.  In  Ceylon,  the 
Padival  Dam  is  1 1  miles  in  length,  and  200  feet  wide  at  the 
base,  30  feet  wide  at  the  crest,  and  70  feet  high  in  places. 
This  dam  is  said  to  have  cost  $6,327,100.  It  is  further 
stated  that  there  are  5000  reservoirs  in  use  in  Ceylon.  There 
are  many  reservoirs  in  use  in  the  United  States,  some  of  which 
have  been  built  by  private  parties,  and  others  by  the 
government.  One  of  the  largest  of  these  is  the  Roosevelt  Dam 
on  the  Salt  River  in  Arizona.  This  dam,  completed  in 
February,  1910,  has  a  capacity  of  1,824,000  acre  feet  of  water. 

Pumping  Water  for  Irrigation.  In  many  places  a  supply 
of  irrigation  water  can  not  be  obtained  without  the  aid  of 
pumps.  Usually  water  secured  by  this  method  is  very 
expensive,  much  more  so  than  the  water  obtained  from 
canals  and  reservoirs  by  gravity.  There  are,  however, 
certain  advantages  in  pumping  the  water  for  irrigation  pur- 
poses. Generally  the  water  supply  is  under  perfect  control, 
which  is  not  always  the  case  with  a  canal  or  reservoir.  Again, 
there  can  be  no  controversies  over  water  rights  or  friction 
with  other  irrigators  who  want  to  use  the  supply  at  the  same 
time. 

Underground  water  is  the  only  source  of  supply  in  certain 
localities.  In  some  places  in  the  West  the  soil  is  so  open  that 
large  streams  disappear  and  flow  away  underneath  the  sur- 
face. When  this  water  can  be  pumped  it  forms  a  valuable 
supply  of  irrigation  water.  In  Egypt  much  of  the  water  is 
elevated  by  hand  labor  either  from  canals  or  from  the  river 
Nile.  In  California  alone,  over  200,000  acres  are  irrigated  by 
water  which  is  pumped,  and  some  400,000  acres  are  so  irri- 
gated in  Texas  and  Louisiana.  There  has  been  a  marked 
development  in  pumps  during  the  past  few  decades.  The 
power  used  includes  animal  power,  steam  engines,  gas  and 
gasoline  engines,  and  electric  power. 


126  AGRICULTURAL  ENGINEERING 

The  cost  of  pumping  water  in  certain  parts  of  the  United 
States  has  been  carefully  studied  by  the  United  States 
Department  of  Agriculture.  In  Santa  Clara  County, 
Cahfornia,  the  cost  of  pumping  water  was  investigated  at 
60  pumping  plants.  The  average  amount  of  water  pumped 
per  acre  was  1.13  feet.  The  average  cost  of  fuel  and  labor 
was  $4.96  per  acre,  and  the  fixed  charge*  was  $5.20,  making 
the  average  cost  of  pumping  water  $10.16  per  acre.  The 
average  efficiency  of  the  pumps  was  41.16  per  cent.  It  was 
found  that  the  cost  of  pumping  was  reduced  by  an  increase 
in  the  size  of  the  plant.  The  cost  of  power  varies  with  the 
cost  of  the  fuel.  In  some  localities  the  steam  engine  is 
cheaper  than  gas  or  gasoHne  engines,  and  in  others  the 
reverse  is  true.  Electricity  is  more  convenient  than  any 
other  power;  but,  unless  it  can  be  furnished  through  a  water 
power  plant  or  some  other  cheap  source,  it  is  the  most 
expensive.  In  Arkansas  and  Louisiana  the  irrigation  water 
for  rice  culture  is  pumped  by  steam.  The  following  table  is 
the  summary  of  the  cost  of  pumping  water  at  17  plants  in 
Louisiana  and  Arkansas,  as  reported  in  Bulletin  201,  Office 
of  Experiment  Stations.  The  general  difference  in  cost  at 
the  Louisiana  plants  and  those  of  Arkansas  is  due  primarily 
to  the  lift  or  height  the  water  had  to  be  pumped.  In  the 
Louisiana  plants  the  Hft  was  about  20  feet,  and  in  the 
Arkansas  plants  about  40  feet. 

Windmills  are  used  quite  extensively  in  certain  localities, 
principally  in  Kansas  and  California.  An  investigation  of 
the  cost  of  windmill  irrigation  at  Garden  City,  Kansas, 
indicates  that  the  cost  per  acre  was  $2.35.  Owing  to  the 
fact  that  power  is  obtained  in  small  units  and  the  cost  of 
installation  and  maintenance  is  very  high  in  the  case  of  wind- 
mills, it  is  doubtful  if  they  will  be  used  extensively. 

*  Covering  all  other  expense,  such  as  interest,  depreciation,  etc. 


IRRIGATION 


127 


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128  AGRICULTURAL  ENGINEERING 

QUESTIONS 

1.  How  are  canals  used  to  secure  a  supply  of  irrigation  water? 

2.  Why  is  the  construction  of  a  canal  important? 

3.  Name  some  of  the  largest  famous  irrigation  canals. 

4.  What  are  the  purposes  of  irrigation  reservoirs? 

6.  How  do  forests  act  as  reservoirs  for  irrigation  waters? 

6.  Describe  some  of  the  largest  irrigation  reservoirs  which  have 
been  constructed. 

7.  What  advantage  has  pumping  over  other  means  of  supplying 
water? 

8.  How  much  does  it  cost  to  pump  water  for  irrigation  under  nor- 
mal conditions? 

9.  What  can  be  said  of  windmills  as  a  source  of  power  for  pumping 
irrigation  water? 


CHAPTER  XXI 
APPLYING  WATER  FOR  IRRIGATION 

Principles  Involved.  In  applying  irrigation  water,  con- 
sideration should  be  given  to  some  of  the  principles  govern- 
ing the  wetting,  puddling,  and  washing  of  the  soil.  If  these 
points  are  not  studied  in  connection  with  each  type  of  soil, 
much  more  water  may  be  used  than  necessary,  and  it 
may  be  used  in  a  way  harmful  to  the  crops.  A  good 
irrigation  farmer  observes  closely  the  effects  of  the  appli- 
cations on  the  soil  and  plant,  and  continually  endeavors 
to  improve  his  methods.  When  water  is  applied  to  the 
surface,  it  starts  to  percolate  downward  and  outward.  If 
the  soil  be  coarse,  the  water  will  travel  almost  directly  down- 
ward, especially  if  the  texture  becomes  more  open  or  coarser 
as  the  depth  increases.  It  is  then  necessary  to  apply  the 
water  to  the  entire  surface  to  get  the  best  results.  When 
water  is  applied  to  a  fine  loam  underlaid  by  a  subsoil  of  very 
fine  texture,  the  water  percolates  downward  slowly  by  grav- 
ity and  spreads  laterally  by  capillarity.  For  this  reason  the 
water  may  effectively  be  applied  to  these  soils  in  furrows 
some  distance  apart. 

When  the  soil  is  very  dry,  the  percolation  downward  is 
less  rapid  than  when  it  is  more  moist.  This  is  accounted  for 
by  the  fact  that  the  air  in  the  soil  must  be  displaced  before 
the  water  can  travel  downward.  This  takes  time,  and  for 
this  reason  a  soil  will  not  take  water  as  rapidly  when  dry  as 
when  moist. 

In  applying  irrigation  water,  great  care  should  be  taken 
net  to  puddle  the  soil,  that  is,  to  cause  the  crumb  structure  W) 

^  129 


130  AGRICULTURAL  ENGINEERING 

be  SO  broken  down  as  to  allow  the  soil  particles  to  run  to- 
gether and  form  a  compact  mass.  Soil  in  such  a  condition  is 
said  to  be  water-tight.  The  air  cannot  enter  a  soil  of  this 
kind,  and  an  aerated  soil  is  essential  in  furnishing  favorable 
conditions  for  plant  growth.  If  too  much  water  is  applied 
to  the  soil,  it  becomes  water-logged  and  suffers  for  the  lack 
of  air  in  the  same  way. 

Preparing  Land  for  Irrigation.  As  irrigation  water  is 
usually  applied  by  the  aid  of  gravity,  great  care  should  be 
used  in  preparing  the  surface  ground  and  the  ditches  and 
small  laterals  necessary  to  convey  the  water  over  the  fields. 
The  proper  slope  must  be  given  to  the  surface  to  give  an  even 
distribution  of  the  water.  For  this  reason  one  of  the  largest 
items  of  expense  involved  in  bringing  land  under  irrigation  is 
the  cost  of  preparing  the  land.  Usually  irrigable  land  is 
covered  with  some  sort  of  growth  which  must  be  removed. 
It  costs  from  $1.50  to  S4  per  acre  to  remove  sage  brush,  which 
is  usually  found  on  the  land  in  the  arid  sections  of  the  United 
States.  The  land  must  be  thoroughly  gone  over  with  graders 
and  other  leveUng  machines  and  worked  until  the  surface  is 
made  a  perfect  plane. 

Dr.  Elwood  Meade  states  that  the  cost  of  preparing  the 
land  for  irrigation  in  the  United  States  varies  from  $3  to  $30 
per  acre.  The  following  table  shows  the  average  cost  of 
preparing  land  for  different  methods  of  irrigation : 

Check  method $  3.60 

Flooding  method 2.75 

Furrow  method 3.50 

Basin  method 4.50 

Methods  of  Appljring  Water.  There  are  many  methods 
of  applying  water  to  irrigated  crops,  and  nearly  all  are 
practiced  in  the  United  States.  The  method  to  be  used  in 
any  particular  case  depends  largely  upon  the  nature  of  the 


IRRIGATION 


131 


Fig.    70.      Flooding    method    of   irrigation. 
(Sep.   514,   U.   S.   Dept.    of  Agr.) 


ground,  the  crops  grown,  the  amount  of  water  available,  kind 
of  soil,  and  other  conditions. 

The  Flooding  Method.  One  of  the  more  general  methods 
of  application  is  known 
as  the  flooding  system. 
It  is  generally  used  on 
land  when  it  is  first  re- 
claimed, even  though 
another  method  is  in- 
tended to  be  used  later. 
Preparing  the  ground 
for  flooding  consists  in 
leveling,  grading,  and  smoothing,  so  that  the  water  will 
flow  readily  over  it  in  sheets.  To  distribute  the  water,  small 
field  ditches,  or  laterals,  are  located  along  the  best  routes. 
These  small  ditches  are  usually  from  50  to  100  feet  apart, 
and  they  generally  follow  grade  lines,  or  contours.  Where 
wG  €"xa-  little  care  is  used  to  control  the  flow 
of  the  water,  the  practice  is  said  to  be 
''wild  flooding."  The  small  ditches 
are  made  with  a  double  moldboard 
plow,  which  turns  a  furrow  on  either 
side.  To  cause  the  water  to  overflow 
from  the  ditch  to  the  side,  a  dam 
must  be  put  in  place.  This  con- 
sists usually  of  a  piece  of  canvas 
nailed  along  one  edge  to  a  strip  of 
wood.  In  other  cases,  the  ditch  may 
be  dammed  by  simply  building  up  a 
small  ridge  of  earth  across  the  ditch. 
The  Check  Method.  The  check  method  of  applying 
water  consists  in  dividing  the  fields  into  sections  each  having 
a  comparatively  level  surface  and  bordered  on  all  sides  by 


Fig.  71.  A  canvas  dam. 
This  dam  has  an  opening 
to  divide  an  irrigating 
stream.  (Bui.  203,  Office 
of   Experiment    Stations.) 


132 


AGRICULTURAL  ENGINEERING 


i 

'  '-'^iM 

Wgf 

^ 

;.:;^_3P| 

m 

^^p^ 

m 

'  *^^^I^H 

1 

Fig-.    72.      A   canvas   dam   in  use.      (Farm- 
er's Bui.    392,   U.   S.    Dept.   of  Agr.) 


low,  flat  levees,  or  ridges. 
Into  these  checks  the 
water  is  turned.  On  level 
ground  these  sections  or 
checks  may  be  made  rec- 
tangular; but  on  sloping 
ground  the  ditch  for  sup- 
plying the  water  must  fol- 
low the  contour  Hues,  in 
which  case  they  are  said 
to  be  contour  checks. 
In  applying  the  water, 

an  opening  is  made  from  the  ditch  into  the  side  of  each 

check  and  the  water 

allowed   to    flow   in 

until  each  is  covered 

to  the  desired  depth. 

Where    the    check 

method  is  followed, 

it   is    customary   to 

have  small  wooden 

outlets  from  the  ditch 

into  the  checks,  with 


Fig.  7; 


Check  method  of  irrigation. 
U.  S.  Dept.  of  Agr.) 


(Sep.  514, 


valves  which  can  be 
operated  to  close  the 
opening  when  de- 
sired. 

Basin  Method. 
The  basin  method  is 
quite  similar  to  the 
check  method.  It 
is    used    principally 

F^g.  74.     Basin  method  of  irrigation.      (Sep.   514,     •         .i         irrin-Q+inn    nf 

u.  s.  Dept.  of  Agr.)  ^'^    ^'^^   irngawuu  Ul 


IRRIGATION 


133 


trees.  A  basin  is  provided  around  the  tree,  with  a  suitable 
ridge  to  hold  the  water,  which  is  then  turned  in  until  a  suffi- 
cient amount  is  applied. 

Border  Method.  The  border  method  is  also  similar  to 
the  check  method  in 
that  the  land  is  di- 
vided into  long  strips, 
and  the  water  is 
turned  into  these 
from  a  ditch  at  the 
end  or  along  the  bor- 
der.    It  is    easy  to 


Fig. 


Border  method  of  irrigation. 


see  that  by  arranging 

these  long  strips  the  work  necessary  in  preparing  ridges  is 

reduced. 

Furrow  Method.  The  furrow  method  of  applying  irri- 
gation water  consists  in  turning  the  stream  of  water  into 
furrows  between  the  rows  of  intertilled  crops.  It  is  more 
generally  employed  than  any  other  method,  with  the  excep- 
tion of  flooding  from  field  laterals.  The  distance  between 
furrows  will  depend  upon  the  character  of  the  soil.  It  is 
customary  to  provide  small  openings  or  pipes  in  the  ridge 

1.  at  the  side  of  the 
supply  ditch  by 
which  the  water  may 
be  turned  into  the 
furrows. 

Subirrigation. 
Upon    first  thought 

Fig.     7f).      Manner    of    placing    tubes    In    ditch     'i        ,„,,1  J     orv«»-.    +1^0  + 
bank   for  furrow  Irrigation.      (Farmer'.s  Bui.   373.     ^^    WOUIQ    SCem    inat 

u.  s.  Dept.  of  Agr.)  ,  subirrigatiou,  or  wa- 

ter applied  to  crops  from  pipes  laid  beneath  the  surface, 
would  be  an  ideal  system.    This  is  not  the  case,  as  such  a 


134 


AGRICULTURAL  ENCflNEERING 


system  is  not  only  expensive  to  install,  but  also  quite  extrav- 
agant in  many  cases  in  the  use  of  water.  This  is  due  to 
the  fact  that  the  water  tends  to  percolate  downward  from 
the  opening  and  so  does  not  saturate  the  soil  satisfactorily. 
Spraying  Method.  Where  irrigation  is  practiced  in  a 
small  way  the  water  may  be  applied  by  spraying.  This 
system  provides  surface  pipes  containing  water  under 
pressure,  whch  may  be  discharged  through  nozzles  in  such  a 
way  as  to  cover  the  entire  surface.  Often  the  pipes  are 
arranged  so  as  to  revolve,  turning  the  nozzles  about  in  such 
a  way  as  to  discharge  in  different  directions  and  thus  reduc- 
ing the  amount  of  pipe  required. 

The  Measurement  of  Water.  Most  of  the  water  used 
in  irrigation  is  sold  to  the  farm  owners,  which  fact  necessi- 
tates that  methods  be  devised  for  its  measurement  and  regu- 
lation. In  addition, 
the  irrigator  should 
know  something  defi- 
nite about  the  amount 
of  water  applied,  in 
order  that  he  may  de- 
termine whether  or 
not  it  is  being  used  as 
efficiently  as  it  should 
be. 

Units  of  Measure- 
ment. One  of  the  most 
satisfactory  units  of 
measurement  from  the 
standpoint  of  the  agri- 
culturist is  the  acre-inch,  which  is  the  amount  of  water  required 
to  cover  an  area  of  one  acre  one  inch  deep.  Thus,  ten  acre- 
inches  is  sufficient  water  to  cover  an  acre  ten  inches  deep, 


Fig:.  77.  A  C'ippolelti  weir  with  water  regis- 
ter in  place  for  measuring  and  recording  the 
head  of  water  over  the  lower  edge  of  the  weir. 
(Bui.   86,   Office  of  Experiment  Stations.) 


IRRIGATION  135 

or  ten  acres  one  inch  deep.  The  principal  advantage  of  this 
unit  lies  in  the  fact  that  a  direct  comparison  may  be  made 
between  the  irrigation  water  applied  and  a  similar  amount 
of  rainfall.  Where  water  is  delivered  from  a  canal,  it  is 
necessary  to  use  a  unit  which  will  indicate  the  rate  of  deUvery. 
The  cubic  foot  per  second  is  a  unit  in  common  use,  and  is 
easily  understood.  The  miner's  inch,  used  in  many  states, 
is  a  unit  whose  value  varies  very  much.  In  Idaho,  Nevada, 
and  Utah,  laws  have  been  enacted  defining  a  miner's  inch 
as  1-50  of  a  cubic  foot  per  second.  In  Arizona,  it  is  1-40 
of  a  cubic  foot  per  second,  and  in  Montana  a  unit  having 
the  same  value  is  called  a  statute  inch  instead  of  a  miner's 
inch.  In  Colorado,  a  cubic  foot  per  second  is  equal  to  38.4 
statute  inches.  Water  is  usually  measured  by  weirs,  which 
are  notches  of  a  certain  form  through  which  the  water  is 
allowed  to  flow.  A  form  of  weir  in  general  use  is  known  as 
the  Cippolletti.  The  amount  of  water  flowing  through  such 
a  weir  may  be  determined  from  the  height,  or  "head,"  of  the 
flow. 

QUESTIONS 

1.  What  are  some  of  the  principles  involved  in  applying  irrigation 
water? 

2.  What  are  some  of  the  essential  features  of  preparing  land  for 
irrigation? 

3.  How  does  the  cost  of  preparing  land  for  irrigation  vary  with 
methods  of  irrigation? 

4.  Describe  the  flooding  method  of  applying  irrigation  water. 

5.  Explain  the  check  method  of  applying  water. 

6.  Describe  basin  and  border  irrigation. 

7.  How  is  irrigation  water  applied  in  furrows? 

8.  Why  is  subirrigation  not  generally  satisfactory? 

9.  How  is  irrigation  water  applied  by  spraying? 

10.  What  are  the  units  in  general  use  for   measuring    irrigation 
water? 

11.  What  is  a  weir? 


CHAPTER  XXII 

IRRIGATION   IN   HUMID   REGIONS,   AND    SEWAGE 
DISPOSAL 

Irrigation  is  generally  practiced  in  those  regions  where  the 
natural  rainfall  is  so  small  as  to  make  it  quite  impossible  to 
grow  crops  without  supplying  water  artificially.  Here  irri- 
gation is  an  absolute  necessity.  In  other  localities,  it  may 
not  be  a  necessity,  but  it  may  be  practiced  profitably  to  sup- 
plement rainfall,  thus  securing  larger  yields.  As  agriculture 
becomes  more  intensive,  it  is  to  be  expected  that  irrigation 
of  this  nature  will  become  more  common. 

The  regions  in  which  the  rainfall  is  very  small  are  said 
to  be  arid;  those  having  sufficient  rainfall  to  produce  good 
crops  under  normal  conditions  are  said  to  be  humid;  and  the 
regions  in  which  the  rainfall  is  scanty  or  limited  are  said  to 
be  semiarid.  It  is  to  be  expected  that  supplementary  irri- 
gation will  be  practiced  more  in  semiarid  regions  than  in 
humid  regions.  However,  if  a  careful  study  be  made  of  the 
distribution  of  rainfall  in  many  so-called  humid  regions,  it 
will  be  found  that,  in  many  years  when  the  demand  for 
moisture  is  the  greatest,  the  rainfall  is  insufficient.  A  study 
of  the  rainfall  at  Philadelphia,  by  Mr.  R.  P.  Teele,  of  the 
Office  of  Experiment  Stations,  shows  that,  although  the 
average  rainfall  for  that  locality  is  large,  the  records  indicate 
that  there  were  periods  of  drouth  during  88  per  cent  of  the 
seasons  for  the  70  years  covered  by  the  investigations,  which 
dry  spells  caused  injury  to  the  crops  that  had  short  growing 
periods.  The  investigations  also  showed  that  all  crops 
received  too  little  water  during  a  third  of  the  years. 

136 


IRRIGATION  137 

In  Europe,  irrigation  has  been  practiced  for  ages  in 
regions  having  rather  large  rainfall.  Meadows  and  pastures, 
especially,  are  irrigated  very  successfully,  and  this  is  com- 
monly practiced  in  Great  Britain,  Holland,  Germany, 
Switzerland,  Italy,  and  France. 

In  some  countries  where  there  is  much  sunshine,  phe- 
nomenal crops  are  grown  through  irrigation.  It  is  reported 
that  in  Italy,  marcite,  a  meadow  crop  made  up  of  a  mixture 
of  clover  and  Italian  rye  grass,  will  yield  from  ten  to  fifteen 
tons  per  acre  of  a  cutting,  for  eight  to  ten  cuttings  per  year. 

There  are  many  small  irrigation  plants  through  the  humid 
portions  of  the  United  States.  Data  collected  by  the  irriga- 
tion investigations  of  the  United  States  Department  of 
Agriculture  indicate  that  about  800  acres  of  meadow  land 
are  irrigated  in  the  humid  regions  of  the  United  States. 
Most  of  the  water  used  is  obtained  from  springs  and  through 
the  diversion  of  streams  by  small  canals  or  dams.  This 
water  is  let  over  the  meadows  in  small  ditches  or  laterals,  and 
is  spread  over  the  same  in  a  manner  similar  to  the  check 
method  of  irrigation.  Irrigation  is  also  generally  practiced 
in  the  growing  of  small  fruits,  which  are  seriously  injured 
by  drouths  that  come  at  the  time  when  the  fruit  is  forming. 

The  truck  farmers  have  also  found  irrigation  a  profitable 
insurance  against  loss  through  drouth.  Professor  F.  H. 
King,  of  the  Wisconsin  experiment  station,  conducted  some 
very  interesting  experiments  in  irrigation  at  Madison,  Wis- 
consin. Over  a  rather  long  term  of  years,  the  average 
increase  in  the  yields  of  grain  was  26.93  bushels  per  acre. 
The  increase  in  the  yield  of  clover  hay  was  23^  tons  per  acre; 
and  of  potatoes,  83.09  bushels  per  acre.  The  cost  of  irrigat- 
ing the  land  was  $6.80  per  acre,  which  cost  did  not  include 
the  interest  on  the  first  investment  for  the  plant.  These 
gains  are  made  up  from  the  average  yield  for  the  State  of 


138  AGRICULTURAL  ENGINEERING 

Wisconsin  and  therefore  are  no  doubt  large,  inasmuch  as  the 
nonirrigated  crops  do  not  generally  receive  the  attention 
given  to  those  which  are  irrigated. 

Irrigation  for  Sewage  Disposal.  In  many  localities  the 
disposal  of  sewage  water  from  cities  is  an  important  problem. 
This  is  especially  true  of  cities  which  are  not  situated  near 
large  bodies  of  water  or  streams  into  which  the  sewage  may 
be  discharged.     In  these  cases,  sewage  irrigation  must  be 


Fig.   78.     Furrow  irrigation  with  sewage  water. 

resorted  to,  and  this  not  only  provides  a  convenient  method 
of  disposal,  but  it  may  be  made  a  matter  of  profit.  Perhaps 
there  is  no  way  of  disposing  of  sewage  more  satisfactorily 
than  by  applying  it  to  the  soil.  The  organic  matter  in 
sewage  water  is  quickly  purified  through  the  agency  of  soil 
organisms,  when  it  is  apphed  to  the  soil  in  a  skillful  manner. 
The  crops  grown  by  sewage  irrigation  vary  widely,  and 


IRRIGATION 


139 


include  grasses,  grains,  potatoes  and  garden  truck.  Of 
these,  grasses  is  the  most  generally  grown;  Itahan  rye  grass, 
especially,  thrives  under  this  form  of  irrigation.  The  success 
of  sewage  irrigation  indicates  that  it  could  be  practiced  more 
generally  than  it  is  at  present. 

For  several  years,  experiments  in  sewage  irrigation  were 
conducted  at  the  Iowa  experiment  station,  in  coHDperation 
with  the  irrigation  investigations  of  the  United  States  Depart- 
ment of  Agriculture.  The  following  table  is  a  siunmary  of  a 
part  of  the  results  obtained.  Two  plots  of  each  crop  were 
grown  under  the  same  conditions,  except  that  one  was  irri- 
gated with  sewage  water  and  the  other  was  not  irrigated  at  all. 


Summary  of  irrigation  experiments  in  Iowa,  showing  increased  yields  by 
the  use  of  sewage  water. 


Kind  of  crop 

Year 

Yield  per  acre; 
not  irrigated 

Amt.  of 

sewage 

water 

applied  in 

irrigation 

Yield  per  acre 

irrigated 

area 

Increase 
yield    per 
A.    by  irri- 
gation 

Cabbage 

Corn 

1907 
1907 
1907 
1908 
1908 
1908 
1909 
1909 
1910 
1910 
1910 

63840  lbs. 
57.8    bu. 
41.4    bu. 
3.15  tons 
11.25  tons 
150.2    bu. 
29.      bu. 
6.67  tons 
.13  tons 
1.42  tons 
39.1    tons 

7  in. 
7  in. 
13.21  ft. 
5.41  ft. 
7.08  ft. 

70430  lbs. 
59.8    bu. 
54.      bu. 
3.49  tons 
12.75  tons 
181.5    bu. 
34.      bu. 
5.6 

1.32  tons 

3.      tons 

59.      tons 

9.5% 
3.4% 
30.4% 
10.7% 
13.3% 
20.8% 
17.2% 
—16.0% 

Barley 

Rye  grass 

Beets,  sugar .... 

Potatoes 

Barley 

Alfalfa 

Blue  grass 

Timothy 

Beets       

111.2% 
50.9% 

During  the  years  1907  and  1908,  irrigation  was  given 
only  when  the  crop  seemed  to  be  in  need  of  moisture.  In 
1910  a  larger  amount  of  water  was  used. 


140  AGRICULTURAL  ENGINEERING 

QUESTIONS 

1.  What  is  meant  by  humid,  semiarid,  and  arid  regions? 

2.  Why  is  irrigation  profitable  in  humid  regions? 

3.  How  have  experiments  proven  that  yields  may  be  increased  in 
humid  regions? 

4.  Does  irrigation  furnish  a  satisfactory  means  of  disposing  of 
sewage  water? 

5.  What  crops  can  be  profitably  grown  with  sewage  irrigation? 

REFERENCE  TEXTS 

Irrigation  Engineering,  by  H.  M.  Wilson, 

Irrigation  and  Drainage,  by  F.  H.  King. 

Irrigation  Institutions,  by  Dr.  Elwood  Meade. 

Irrigation  Farming,  by  L.  Wilcox. 

Primer  of  Irrigation,  by  D.  H.  Anderson. 

Bulletins  of  the  United  States  Department  of  Agriculture. 


PART  FOUR-ROADS 


CHAPTER  XXIII 
IMPORTANCE  OF  ROADS 

History.  The  object  of  a  road  is  to  furnish  a  way  for 
travel  and  the  transportation  of  products.  The  art  of  road 
construction  runs  back  before  the  time  when  history  was 
written,  and  roads  have  appeared  in  a  country  whenever  its 
people  have  shown  a  tendency  to  become  civilized. 

There  is  abundant  evidence  at  hand  to  show  that  a  paved 
road  existed  in  Egypt  as  early  as  4000  years  b.  c.  No  doubt 
the  material  for  the  great  pyramids  was  transported  over  a 
part  of  this  road.  Much  of  the  history  of  Carthage  and 
Rome  relates  to  the  construction  of  their  roads,  which  were 
used  for  the  transportation  of  soldiers  and  suppUes.  The 
success  of  the  Roman  Empire  as  a  great  nation  is  largely  due 
to  its  system  of  improved  roads,  over  which  its  armies  could 
be  moved  quickly.  Ancient  Rome  had  no  less  than  372 
great  roads,  aggregating  about  50,000  miles,  and  which,  it 
has  been  estimated,  would  cost  under  modem  conditions  as 
much  as  $5,000,000,000.  All  the  civiHzed  nations  through- 
out the  world  have  given  the  matter  of  road  construction 
careful  attention. 

The  Extent  of  Our  Roads.  There  are  in  the  United 
States  2,150,000  miles  of  public  roads.  About  one-half  of 
this  mileage,  however,  is  but  little  used,  and  no  doubt  in 
time  a  part  will  be  found  unnecessary  and  will  be  discon- 
tinued. 

141 


142  AGRICULTURAL  ENGINEERING 

Benefits  of  Good  Roads.  The  benefits  of  good  roads  to 
agriculture  are  far-reaching  and  are  worthy  of  careful  and 
extended  study.  The  benefits  are  largely  financial  in  char- 
acter, and  so  the  value  of  good  roads  may  be  estimated  in 
dollars  and  cents.  There  are  other  benefits  which  may  be 
styled  social,  and  are  those  which  tend  to  add  to  the  comforts 
of  country  life. 

FINANCIAL  BENEFITS 

Cost  of  Transportation.  The  most  important  and  funda- 
mental benefit  to  be  derived  from  a  system  of  good  roads  lies 
in  the  reduction  of  the  cost  of  transportation  of  farm  and 
other  products  which  must  be  hauled  over  them. 

Referring  to  Bulletin  49  of  the  United  States  Office  of 
Public  Roads,  it  is  found  that  during  the  crop  year  of  1905 
and  1906  there  were  42,743,500  tons  of  farm  products,  con- 
sisting of  barley,  corn,  cotton,  flax  seed,  hemp,  hops,  oats, 
peanuts,  rice,  tobacco,  wheat,  and  hay,  hauled  over  the 
roads  from  the  farms  to  the  shipping  points.  This  estimate 
does  not  include  the  transportation  of  products  from  the 
town  back  to  the  farm,  nor  does  it  include  live  stock,  truck- 
farm  products,  and  fruit.  A  careful  investigation  by  the 
Office  of  Public  Roads  indicates  that  the  present  cost  of 
transportation  is  about  25  cents  per  ton  mile,  that  is,  the 
cost  of  hauling  one  ton  one  mile.  If  a  small  saving  could  be 
secured  in  this  cost  of  transportation  per  ton  mile,  the  aggre- 
gate saving  for  a  year  would  be  enormous. 

With  a  system  of  good  roads  it  is  possible  to  make  a  great 
reduction  in  this  cost  of  transportation.  The  cost  varies 
with  the  kind  of  road.  The  investigation  shows  that  over 
broken-stone  roads  in  good  order  the  cost  is  only  8  cents  per 
ton;  on  broken-stone  roads  in  ordinary  condition,  the  cost  is 
11.09  cents;  on  earth  roads,  with  ruts  and  mud,  the  cost  is 


ROADS  143 

39  cents;  and  on  sandy  roads,  the  cost  is  as  much  as  64  cents 
per  ton  mile.  The  average  haul  for  farm  products  in  the 
United  States  is  about  9  miles.  It  is  estimated  by  Mr.  L.  W. 
Page,  director  of  the  United  States  Office  of  Pubhc  Roads, 
that  if  the  cost  of  hauling  in  the  United  States  could  be 
reduced  from  25  cents  to  12  cents  per  ton  mile,  the  annual 
saving  in  moving  the  twelve  principal  farm  crops  would 
amount  to  $51,000,000.  He  further  estimates  that  the  total 
amount  of  freight  hauled  over  country  roads  in  a  year 
reaches  265,000,000  tons,  and  that  the  total  cost  of  haul- 
ing this  on  the  roads  approximates  $500,000,000.  In  this  case 
the  total  saving  in  reduction  of  the  cost  of  hauhng  from  25 
cents  to  12  cents  per  ton  mile  would  be  $250,000,000  annually. 

In  this  connection,  attention  is  called  to  the  fact  that  it 
would  not  be  practical  to  improve  all  country  roads.  Mr. 
Page  estimates  that  the  traffic  is  such  that  the  cost  of  hauling 
freight  could  be  reduced  to  15  cents  per  ton  mile  if  25  per 
cent  of  the  roads  were  improved.  He  estimates  that  the 
total  cost  of  improving  this  percentage  of  the  total  mileage 
of  roads  would  be  $2,000,000,000. 

A  striking  example  of  importance  of  country  roads  is  set 
forth  by  the  fact  that  it  costs  the  American  farmer  3.06 
cents  more  per  bushel  to  haul  his  wheat  crop  a  distance  of 
9.4  miles  to  market,  than  it  costs  to  ship  by  regular  steamship 
Unes  from  New  York  to  Liverpool,  a  distance  of  3100  miles. 

Influence  on  Markets.  Good  roads  have  a  decided 
influence  upon  markets  in  several  ways.  First,  a  wider 
variety  of  crops  may  be  grown,  and  marketed  at  the  center 
from  which  good  roads  radiate.  This  tends  to  increase  about 
cities  the  area  in  which  certain  crops,  such  as  fruit  and 
truck  crops,  can  be  grown.  This  is  also  true  of  dairying,  as 
a  dairy  farm  can  be  located  farther  from  the  city,  if  good 


144  AGRICULTURAL  ENGINEERING 

roads  are  provided  between  the  farm  and  the  city,  enabling 
the  farmer  to  deliver  his  products  quickly  and  cheaply. 

Again,  good  roads  permit  the  marketing  of  farm  products 
when  the  prices  are  most  favorable.  In  many  localities, 
when  prices  are  best  the  farmer  is  unable  to  deliver  his 
crops,  owing  to  the  fact  that  the  roads  are  impassable. 

Also,  good  roads  furnish  to  the  farmer  a  wider  choice 
of  markets.  With  good  roads  prevailing,  it  is  possible  for 
him  to  deliver  his  products  to  any  one  of  several  centers. 
Good  roads  tend  to  equalize  the  supply  of  produce  on  any 
given  market  between  favorable  and  unfavorable  seasons  of 
production.  Lastly,  good  roads  tend  to  equalize  local  mer- 
cantile business  throughout  the  different  seasons  of  the  year. 
In  some  instances  little  business  can  be  done  when  the  farmers 
are  unable  to  get  into  town  on  account  of  the  bad  roads. 

Good  roads  tend  to  equalize  railroad  traffic.  Often  dur- 
ing the  period  of  bad  roads,  farm  products  are  not  delivered, 
and  the  railroads  have  Httle  to  do.  Then  when  the  roads 
become  passable  to  heavy  traffic,  farmers  sell  their  products 
in  such  large  quantities  as  to  cause  a  congestion  of  traffic*. 

SOCIAL  BENEFITS 

Social  Benefits.  Perhaps  of  equal  importance  with  the 
financial  benefits  to  be  derived  from  the  system  of  good 
roads  are  the  social  benefits.  Good  roads  permit  more  easy 
intercourse  among  country  people,  and  between  country 
people  and  city  people.  Good  roads  place  the  farm  nearer 
the  city,  thus  overcoming  to  a  certain  extent  some  of  the  dis- 
advantages of  country  life.  They  are  also  a  factor  in  assist- 
ing in  the  development  of  the  consolidated  rural  school,  and 
facilitate  the  rural  mail  delivery.  The  United  States  Post 
Office  Department  will  not  estabfish  or  continue  a  rural 


ROADS  145 

mail  route  where  the  roads  are  not  maintained  at  a  certain 
standard. 

Value  of  Farms.  It  is  often  stated  that  good  roads  tend 
to  increase  the  value  of  farms;  and  some  instances  are  referred 
to  where,  upon  the  completion  of  a  good  road  past  a  farm,  its 
selling  value  was  at  once  materially  increased.  No  doubt 
this  can  be  considered  the  measure  of  the  value  of  the  bene- 
fits which  have  been  discussed. 

Requisites  of  a  Good  Road.  A  good  road  is  one  over 
which  travel  may  take  place  with  ease  and  comfort,  and  one 
over  which  freight  or  products  may  be  hauled  at  a  low  cost. 
Furthermore,  a  good  road  must  not  be  prohibitive  in  cost, 
and  must  require  a  minimum  of  attention  for  its  maintenance. 
The  following  are  some  of  the  more  important  features  which 
should  be  considered : 

Smoothness.  No  road  can  be  considered  a  good  road 
unless  it  presents  a  smooth  surface  over  which  vehicles  may 
travel  without  jar  or  vibration.  Smoothness  is  also  essential 
to  the  moving  of  loads  with  the  least  effort. 

Rigidity.  When  a  loaded  vehicle  rests  upon  a  road  sur- 
face, the  wheels  sink  into  the  surface  more  or  less.  If  the 
road  surface  is  soft,  the  wheels  w^U  sink  in  deeply,  and  the 
vehicle,  as  it  is  drawn  forward,  will  be  compelled  to  roll 
against  an  incline.  The  amount  of  resistance  which  the  load 
furnishes  varies  with  the  depth  that  the  wheels  cut  into 
the  surface.  Thus,  the  road  which  will  most  prevent  the 
wheels  from  cutting  in  will  furnish  the  least  resistance. 
•  When  a  loaded  vehicle  is  moved  up  an  incline,  it  is  noticed 
that  the  resistance  is  increased  proportionately  to  the  grade. 
Thus  if  a  load  of  1000  pounds  be  moved  up  a  10  per  cent 
grade,  an  extra  force  equal  to  10  per  cent  of  the  load  will  be 
required  to  overcome  the  resistance  due  to  the  grade.     It  is 


146  AGRICULTURAL  ENGINEERING 

here  necessary  to  explain  that  a  grade  of  10  per  cent  is  one 
which  has  a  rise  of  10  feet  in  100  feet  of  length. 

Cost.  A  good  road  must  not  cost  more  than  a  certain 
amount,  or  the  value  of  its  service  will  not  cover  the  interest 
on  the  investment.  Thus  the  best  road  for  certain  conditions 
may  be  one  that  is  comparatively  cheap,  inasmuch  as  the 
amount  of  traffic  will  not  justify  the  expenditure  for  a  more 
expensive  road.  A  good  road  will  be  durable,  and  will 
require  little  attention  to  repair  it.  For  this  reason  great 
care  should  be  used  to  see  that  the  road  is  well  constructed 
and  made  of  durable  materials. 

QUESTIONS 

1.  What  is  the  object  of  a  road? 

2.  What  is  the  mileage  of  roads  in  the  United  States? 

3.  What  two  classes  of  benefits  may  be  derived  from  good  roads? 

4.  What  is  meant  by  the  "ton  mile"? 

5.  What  is  the  average  cost  of  transportation  in  the  United  States? 

6.  How  does  the  cost  of  transportation  vary  with  the  kind  of  road? 

7.  In  what  way  will  good  roads  influence  the  markets? 

8.  How  may  good  roads  be  of  benefit  in  a  social  way? 

9.  What  are  the  requisites  of  a  good  road? 

10.  How  much  money,  according  to  the  estimate  of  Mr.  Page, 
could  be  spent  each  year  in  the  improvement  of  roads? 

Note.  The  student  should  obtain  statistics  in  regard  to  roads  in 
his  own  state,  county,  and  township;  the  mileage,  the  funds  spent,  etc. 


CHAPTER  XXIV 
EARTH  ROADS 

Extent.  Of  the  total  mileage  of  roads  in  the  United 
States,  about  2,000,000  miles  are  unimproved,  or  earth 
roads.  It  is  evident  that  a  large  percentage  of  these  roads 
will  remain  unimproved  for  a  long  time,  and  for  this  reason 
earth  roads  are  worthy  of  the  most  careful  attention.  By 
the  term  ** earth  roads"  is  meant  roads  made  of  native  soil 
and  whose  surface  is  loam  or  clay.  Obviously  the  earth 
road  is  the  cheapest  form  of  road.  It  is  possible  to  construct 
a  fairly  good  road  out  of  native  soil,  and  such  a  road  in  most 
cases  furnishes  the  very  best  foundation  for  an  improved 
road  with  a  hard  surface  of  sand  or  gravel. 

Construction  of  an  Earth  Road.  The  subject  of  earth 
roads  naturally  divides  itself  into  two  divisions,  earth-road 
construction  and  earth-road  maintenance.  The  first  applies 
to  the  preparing,  constructing  or  building  of  the  road,  and  the 
last  to  its  maintenance  or  repair. 

Drainage.  It  is  often  stated  that  the  construction  of 
earth  roads  consists  primarily  in  providing  adequate  drain- 
age. When  considered  in  the  broadest  sense,  drainage 
would  include  not  only  underdrainage,  but  also  surface 
drainage.  Underdrainage  is  quite  necessary  in  any  kind  of 
road,  and  especially  in  an  earth  road,  and  if  not  provided 
naturally  it  should  be  provided  artificially.  In  constructing 
earth  roads  it  is  desirable  to  maintain  as  hard  a  surface  as 
p)Ossible  with  the  materials  used,  and  water  tends  to  soften 
them.  The  supporting  power  of  earth  depends  largely  upon 
the  dryness  of  the  soil.    A  good  surface  may  be  prepared,  yet 

147 


148 


AGRICULTURAL  ENGINEERING 


if  there  is  water  beneath  it  the  water  will  come  up  by  capil- 
lary action  and  soften  the  road  until  its  supporting  power  is 
lost.  Again,  the  action  of  frost  is  greater  when  the  road  sur- 
face is  full  of  water.  Freezing  causes  the  roadbed  to  expand 
and  heave,  tending  to  soften  it.  Thus  it  is  highly  important 
that  soil  in  which  the  ground  water  stands  within  3  or  4  feet 
of  the  surface  be  drained  with  a  tile  drain.  This  is  generally 
accomphshed  by  placing  a  hne  of  tile  at  one  side  of  the  road, 
under  the  side  ditch,  although  sometimes  it  is  placed  beneath 
the  middle  of  the  road.  The  former  location  is  preferable 
for  several  reasons.  First,  the  ditch  does  not  need  to  be  as 
deep.  Second,  in  case  of  repairs  the  tile  is  easier  to  get  at 
than  it  would  be  if  it  were  located  underneath  the  middle  of 
the  road;  and,  if  it  is  found  necessary  to  take  it  up,  traffic  will 
not  be  interfered  with.  Third,  in  a  properly  constructed 
earth  road  the  water  which  flows  on  the  surface  is  conveyed 
rapidly  to  one  side  by  the  slope  or  crown  of  the  road. 


F/OST  Cc/tss 
Section  in  Cut 


Cm^n-r per  root 


Section   in  Fill 

Fig.    79.      Cro.ss   sections   of   earth    roads,    as    recommended   by    the    Iowa 
Highway   Commission. 

Where  thorough  drainage  is  needed,  it  may  bfe  advisable 
to  place  a  tile  Une  at  each  side  of  the  road,  but  under  ordi- 
nary circumstances  one  line  of  tile  ought  to  be  sufficient.  In 
providing  tile  drainage,  care  should  be  taken  to  see  that  the 
tile  is  of  ample  size  to  meet  the  requirements  of  the  area  to  be 


ROADS  149 

drained.  Where  the  road  is  on  a  hillside,  seepage  water, 
which  often  causes  a  wet  road,  may  be  intercepted  by  locat- 
ing the  tile  line  at  the  upper  side. 

Side  Ditches.  In  the  construction  of  earth  roads,  side 
ditches  are  provided  to  receive  the  water  and  carry  it  along 
the  road  until  points  are  reached  where  it  may  be  discharged 
into  natural  channels.  An  even  grade  or  slope  should  be 
given,  so  that  the  water  will  not  collect  in  puddles  in  the  side 
ditches.  It  is  impossible  to  maintain  a  good  road  under 
such  conditions.  These  ditches  should  be  of  sufl5cient 
capacity  to  care  for  the  water.  They  should  be  so  con- 
structed as  not  to  be  dangerous  to  vehicles  when  driven  into 
them.  The  outside  bank  should  not  be  so  steep  as  to  cause 
the  soil  to  cave  into  the  ditch  and  partially  stop  the  flow  of 
water.  Side  ditches  should  be  easily  constructed  and  cleaned 
with  the  common  road  machines.  It  is  desirable  that  they 
be  of  such  form  as  to  permit  the  mowing  of  weeds  in  them  with 
a  common  mower.  In  some  locahties  it  is  desirable  that  the 
side  ditches  have  a  form  that  will  hold  snow  during  the  winter 
months,  facilitating  sled  traffic.  A  good  form  for  the  side 
ditch  is  the  V  shape,  with  the  outside  bank  having  a  slope  of 
IJ/^  to  1  and  the  inside  bank  with  a  slope  of  3  to  1,  as  shown 
in  the  accompanying  cross-section  of  an  earth  road. 

The  Crown.  It  is  highly  important  that  the  middle  of 
the  earth  road  be  higher  than  the  sides,  which  will  cause  the 
surface  water  to  drain  quickly  to  each  side  and  not  lie  on  the 
surface  and  soften  it.  This  oval  part  of  the  road  is  usually 
called  the  crown.  The  road  should  not  only  be  oval,  but 
should  also  be  smooth  so  that  the  water  will  not  he  in  pockets 
on  the  surface.  It  is  not  so  important  that  the  crown  be  of  a 
particular  form,  except  to  secure  uniformity  of  construction, 
but  it  is  important  that  it  be  smooth  and  that  there  shall  be 
some  slope  to  each  side.    If  the  slope  be  too  steep,  the  travel 


150  AGRICULTURAL  ENGINEERING 

will  have  a  tendency  to  concentrate  at  the  middle  of  the  road, 
which  in  a  very  short  time  causes  ruts.  A  slope  of  J^  to 
1  inch  to  the  foot,  as  shown  in  the  accompanying  sketch,  is 
customary. 

Road  Maintenance.  In  order  to  keep  the  earth  road  in 
the  best  possible  condition,  it  is  necessary  that  the  oval 
shape  of  the  surface  be  maintained,  and  that  ruts  be  pre- 
vented from  forming.     To  do  this,  the  roads  must  receive 


Fig.  80.     An  earth  road  maintained  in  good  condition  by  the  road  drag:. 

practically  constant  attention.     The  best  device  for  keeping 
an  earth  road  smooth  is  the  road  drag. 

The  Road  Drag.  The  road  drag  is  a  device  for  smoothing 
earth  roads.  It  is  sometimes  called  the  King  drag,  as  its 
use  has  been  urged  by  D.  Ward  King,  of  Maitland,  Missouri. 
Its  construction  will  be  described  later.  The  drag  is  usually 
drawn  with  the  blades  at  an  angle  with  the  direction  of  travel^ 


ROADS 


151 


so  that  the  soil  which  is  carried  out  by  the  mud  that  sticks 
to  the  wheels  may  be  replaced  and  the  general  wear  repaired. 
Width  of  Earth  Roads.  The  right  of  way  provided  in 
most  states  for  public  roads  varies  from  40  to  66  feet.  This  is, 
perhaps,  more  land  than  is  needed  for  that  purpose,  in  most 
instances.  It  is  unusual  to  improve  more  than  about  36 
feet  of  this  right  of  way,  making  each  side  ditch  about  9  feet 
wide  and  the  crown  proper  18  feet  wide. 


Fig.    81. 


A  typical   condition   of  an  earth   road  on   which   the   drag  has 
not  been  used. 


Earth  Road  Grades.  The  grade  of  earth  roads  may  be 
greater  than  those  of  roads  surfaced  with  stone  or  similar 
material,  because  the  loads  which  are  hauled  on  level  earth 
roads  are  not  as  great  as  those  usually  hauled  on  hard  roads, 
owing  to  the  fact  that  the  roUing  resistance  due  to  the  softer 
road  surface  is  greater.  Thus  the  smaller  loads  adapted  to 
earth  roads  may  be  hauled  up  steeper  grades  with  the  same 


152  AGRICULTURAL  ENGINEERING 

increase  of  effort  that  larger  loads  require  on  lower  grades. 
It  is  of  course  desirable  to  keep  the  grade  as  low  as  possible, 
but  different  locaUties  have  different  standards  for  the  maxi- 
mum grade.  This  maximum  varies  from  10  per  cent  for 
roads  used  but  Httle,  to  4  and  6  per  cent  for  those  on  which 
the  traffic  is  heavy. 

The  drag  can  be  used  to  the  best  advantage  following 
ra'ns,  when  the  soil  is  still  moist.  It  then  has  a  better 
smoothing  action  and  the  earth  scraped  into  the  low  places 
is  easily  compacted.  Roads  which  are  dragged  continu- 
ously for  a  term  of  years  become  very  dense  and  hard. 

QUESTIONS 

1.  What  is  the  mileage  of  earth  roads  in  the  United  States? 

2.  Why  should  earth  roads  be  given  careful  attention? 

3.  What  are  the  two  divisions  of  the  subject  of  earth  roads? 

4.  Why  is  the  drainage  of  earth  roads  important? 

5.  How  much  slope  should  the  crown  of  the  road  have  toward  the 
side  ditches? 

6.  Is  it  important  that  the  crown  be  of  any  particular  shape  or 
form? 

7.  What  will  be  the  result  if  the  sides  of  the  crown  are  given  too 
much  slope? 

8.  How  should  earth  roads  be  maintained? 

9.  What  is  a  good  width  for  a  country  earth  road? 

10.  What  should  be  the  maximum  grade  for  earth  roads? 

11.  Explain  the  action  of  the  road  drag. 


CHAPTER  XXV 

SAND-CLAY  AND  GRAVEL  ROADS 

Clay  Roads.  By  careful  construction  and  continued  care 
an  earth  road  may  be  made  fairly  satisfactory.  This  is  true 
where  such  a  road  is  made  of  clay.  The  construction  and 
maintenance  of  a  clay  road  consist  primarily  in  providing 
drainage.  Such  a  road  should  be  kept  as  dry  as  possible. 
It  should  have  sufficient  slope  from  the  center  toward  the 
sides  to  insure  quick  surface  drainage  to  the  side  ditches; 
and,  as  far  as  practical,  underdrainage  should  be  provided  to 
carry  off  the  water  that  comes  up  from  below.  At  best,  how- 
ever, the  clay  road  is  not  highly  satisfactory.  During  the 
wet  weather  it  becomes  soft,  and  owing  to  the  stickiness  of 
the  clay  the  surface  is  rapidly  destroyed. 

Sand  Roads.  In  many  localities  the  surface  of  the  roads 
is  composed  largely  of  sand.  Sand  roads  present  an  entirely 
different  problem  from  clay  roads;  they  are  at  their  worst 
when  dry,  and  are  best  when  moist.  For  this  reason  some 
skilled  highway  engineers  advise  that  sand  roads  be  made 
flat,  or  without  a  crown.  Straw,  sawdust,  and  other  mate- 
rials are  added  to  the  sand  in  order  to  hold  the  moisture, 
causing  the  sand  to  remain  as  compact  as  possible.  It  is 
also  noticed  that  sand  roads  are  best  when  shaded  by  trees. 

Sand-Clay  Roads.  Where  clay  roads  and  sand  roads 
exist  in  the  same  locality,  it  has  been  observed  that  nearly 
always  there  is  a  good  piece  of  road  between  the  stretch  of 
clay  road  and  the  stretch  of  sand  road.  This  would  indicate 
that  a  mixture  of  sand  and  clay  makes  a  better  road  surface 

153 


154  AGRICULTURAL  ENGINEERING 

than  either  one  alone,  and  it  has  been  demonstrated  fully 
that  this  is  true.  In  constructing  the  sand-clay  road,  suffi- 
cient clay  is  added  to  the  sand,  or  sand  to  the  clay,  as  the  case 
may  be,  to  fill  the  open  spaces  between  the  sand  particles 
with  clay,  causing  the  mixture  to  form  into  a  very  dense  and 
impervious  layer.  Tests  should  be  made  to  determine  the 
amount  of  clay  which  must  be  added  to  the  sand,  or  the 
amount  of  sand  which  must  be  added  to  the  clay.  The  re- 
quired material  is  hauled  to  the  roads  to  be  improved  and  the 
mixture  made  by  plowing,  harrowing,  and  rolling.  If  after  a 
time  it  is  noticed  that  the  road  surface  balls  up  and  sticks  to 
the  wheels  of  the  vehicles  driven  over  it,  there  is  not  a  suffi- 
cient amount  of  sand  in  the  mixture.  On  the  other  hand,  if 
during  the  dry  weather  the  surface  becomes  loose,  it  would 
indicate  that  more  clay  should  be  added.  Sand-clay  roads 
are  very  cheap,  often  their  cost  does  not  exceed  more  than 
$100  to  $200  per  mile  and  seldom  exceeds  $400  per  mile. 
The  sand-clay  road  is  simply  a  step  toward  the  gravel  road. 

Gravel  Roads.  Gravel  consists  of  particles  of  stone 
which  have  been  rounded  by  the  action  of  water  and  ice, 
and  which  are  deposited  in  banks.  Gravel  of  the  right  kind 
is  a  material  from  which  a  very  satisfactory  road  may  be 
constructed.  It  is  not  suited,  however,  to  heavy  traffic. 
It  is  suited  to  average  country  conditions,  and  in  many 
localities  where  gravel  can  be  had  conveniently  it  is  the  most 
desirable  material  to  use. 

Durability  of  Gravel.  Gravel  that  is  satisfactory  for  the 
surfacing  of  roads  should  be  durable  and  not  so  soft  as  to  be 
ground  into  dust  by  much  traffic,  neither  should  it  be  so 
brittle  as  to  be  easily  shattered  or  broken.  As  a  general 
rule,  most  gravel  may  be  depended  upon  to  be  fairly  durable, 
for  if  it  were  not  so  it  would  not  exist  as  gravel  after  having 


ROADS  155 

undergone  the  test  placed  upon  it  in  its  formation  and  trans- 
portation by  water  and  ice. 

Size  of  Gravel.  It  is  desirable  that  the  pebbles  in  the 
gravel  for  road  surfacing  be  not  too  large.  It  is  customary 
to  screen  out  all  pebbles  or  stones  larger  than  ^  to  1  inch  in 
diameter.  In  some  cases  where  larger  pebbles  exist  they 
are  screened  out  and  used  for  the  first  courses  in  the  con- 
struction of  the  road  bed.  If  large  pebbles  or  stones  are 
left  in  the  gravel  they  are  quite  apt  to  come  to  the  surface 
through  the  action  of  the  traffic  and  of  frost.  Gravel 
should  also  vary  in  size,  so  that  there  will  be  small  pebbles 
to  fill  the  open  spaces  between  the  larger  ones,  and  in 
turn  the  space  between  the  smaller  pebbles  should  be  filled 
with  sand  grains.  When  the  gravel  varies  in  size  in  this 
manner  a  very  dense  mixture  is  obtained,  which  is  ideal  for 
road  material.  In  some  cases  where  the  different  sized 
pebbles  do  not  exist  naturally  in  the  proper  proportion  to 
make  a  dense  mixture,  it  may  be  profitable  to  screen  the 
gravel  and  remix  it  more  nearly  as  it  should  be. 

The  Binder.  In  order  that  the  gravel  shall  form  a 
satisfactory  surfacing  material  for  a  road,  it  must  contain  or 
be  mixed  with  some  material  which  will  hold  the  pebbles 
together.  In  most  instances  this  binding  material  is  clay. 
Clay  exists  to  some  extent  in  all  gravels.  When  the  gravel 
will  stand  vertically  in  the  bank,  and  when  it  resists  the 
action  of  frost  and  must  be  loosened  with  a  pick,  it  is  quite 
likely  to  contain  the  proper  amount  of  binding  material.  If 
a  sufficient  amount  of  clay  is  not  present  to  fill  the  open 
spaces  between  the  pebbles  and  cause  them  to  be  packed 
into  a  dense  structure,  additional  clay  should  be  added. 
Clay  has  several  characteristics  which  recommend  it  as  a 
binding  material.  It  is  cheap,  can  be  easily  reduced  to  a 
finely  divided  state,  and  is  usually  found  to  a  more  or  less 


156  AGRICULTURAL  ENGINEERING 

extent  in  the  gravel.  On  the  other  hand,  it  has  some 
undesirable  characteristics.  It  loses  its  binding  power  when 
dry,  and  is  susceptible  to  the  action  of  frost.  In  many  cases 
other  kinds  of  binders  are  used.  Stone  dust  has  excellent 
cementing  properties  and  is  considered  better  than  clay, 
but  is  more  expensive.  As  will  be  explained  in  the  chapter 
on  stone  roads,  automobiles  have  introduced  many  new 
problems  in  connection  with  road  construction.  Many 
forms  of  binders  and  dust  preventives  are  being  experi- 
mented with.  Bitumen,  tar,  crude  oils,  and  chlorides  are 
used  to  hold  the  gravel  together. 

Drainage.  A  good  gravel  road  must  be  thoroughly 
underdrained  if  it  is  to  be  satisfactory.  The  method  of 
draining  does  not  differ  materially  from  that  described  for 
earth  roads.     Many  mistakes  have  been  made  by  those 


6rct,o'^  .n    Cut 

Fig.    82.     Cross  section   of   gravel   road.      (Iowa    Highway    Commission.) 

having  the  matter  of  road  construction  in  hand,  by  applying 
surfacing  material  to  a  road  which  needed  underdrainage 
badly,  and  so  the  material  did  not  produce  the  results  which 
were  hoped  for.  The  ground  water  coming  up  from  below 
softened  the  surface,  and  the  gravel  was  forced  down  into 
the  earth  until  it  entirely  disappeared.  Gravel  roads  should 
have  sufficient  amount  of  crown  or  lateral  slope  to  secure  the 
rapid  drainage  of  all  surface  water  to  the  side  ditches.  The 
amount  of  slope  is  usually  given  as  3^  to  1  inch  to  one  foot  of 
width. 

Surface  Construction.    There  are  two  general  methods  of 
surfacing  roads  with  gravel.     The  cheapest  method  is  known 


ROADS  157 

as  surface  construction.  In  this  method  the  gravel  is  hauled 
and  dumped  on  the  prepared  road  bed,  which  usually  is  an 
earth  road,  and  the  packing  is  left  to  the  traffic.  Sometimes 
little  attention  is  given  to  the  matter  of  smoothing  and 
spreading  the  gravel. 

The  thickness  of  surface  gravel  applied  in  this  manner 
varies  from  3  to  6  inches  at  the  center,  usually  tapering  down 
to  a  less  thickness  at  the  sides.  It  is  considered  the  best 
practice  to  apply  the  gravel  in  two  layers;  thus  if  the  total 
thickness  of  six  inches  of  gravel  is  to  be  apphed,  it  will  be 
spread  in  two  layers 
three  inches  each.  After 
the  first  has  been  spread, 
sufficient  time  should  be 
allowed  for  the  traffic 
to  pack  it  quite  thor- 
oughly before  the  second 
layer  is  spread. 

Trench  Method.  In 
the  trench  method  the 
road  surface  is  carefully 
graded  and  rolled  to  re- 
ceive the  gravel.  Usually 

banks     are     provided     at  Fig.    83.     Model    of  a   gravel   road   illus- 

.,           .J          I-    1         -n    1-    u  trating  the  trench  method  of  construction. 

trie    side  WniCn  will   nOla  a  shows  prepared  sub-grade;  B,  first  course 

,1                        1               xu                J  '^f  gravel;  C,  upper  course  of  gravel.      (Bui. 

the  gravel  on  the  road  se,  omce  of  pubiic  Roads,  u.  s.  Dept.  of 
proper.     In  trench  con-  ^^^'^ 

struction  the  gravel  is  usually  placed  in  two  or  more  layers, 
the  first  being  composed  of  coarse  pebbles,  and  is  thor- 
oughly rolled  with  a  heavy  roller  before  the  other  courses 
are  applied.  This  form  of  construction  gives  a  finished 
road  at  once,  and  for  this  reason  is  more  desirable  than  the 
surface  method.     This  is  much  more  expensive,  however. 


158  AGRICULTURAL  ENGINEERING 

Cost  of  Gravel  Roads.  The  cost  of  gravel  roads  varies 
widely,  depending  largely  upon  the  availability  of  gravel. 
The  method  of  construction  is  another  important  factor. 
The  amount  of  gravel  used  varies  widely  with  different  con- 
struction. In  some  cases  as  httle  as  1-10  of  a  yard  of  gravel 
may  be  appUed  per  foot  of  length.  In  other  cases  a  cubic 
yard  may  be  applied  per  foot. 

Roads  may  be  graveled  hghtly  by  the  surface  method  at 
a  cost  of  from  $200  to  $500  per  mile.  Where  the  roads  are 
constructed  by  the  trench  method,  the  cost  usually  varies 
from  $1000  to  $2000,  but  it  may  run  as  high  as  $3000  per 
mile. 

Maintenance  of  Gravel  Roads.  Gravel  roads  should  be 
kept  smooth  and  oval  by  the  use  of  the  road  drag.  The  road 
drag  is  not  needed  as  often  on  gravel  as  on  earth  roads,  yet 
pockets  and  ruts  should  not  be  allowed  to  form.  From  time 
to  time  additional  gravel  should  be  added  to  the  surface. 

When  repairing  gravel  roads  in  this  manner,  it  is 
customary  to  apply  about  two  inches  of  gravel  at  a  time, 
except  at  the  places  where  the  road  has  been  destroyed,  in 
which  case  it  will  be  necessary  to  use  more  gravel.  The 
length  of  time  in  which  the  gravel  road  may  go  without  an 
application  of  additional  material  varies  so  much  with  the 
traffic,  grade  of  materials  used,  and  other  conditions,  that 
no  attempt  will  be  made  to  suggest   an  average  period. 

QUESTIONS 

1.  Under  what  conditions  is  the  clay  road  at  its  best? 

2.  How  is  a  sand  road  improved? 

3.  What  principle  is  involved  in  the  construction  of  the  sand-clay 
road? 

4.  How  much  does  a  sand-clay  road  cost? 

5.  To  what  conditions  is  the  gravel  road  adapted? 

6.  What  are  the  requisites  of  good  road  gravel? 


ROADS  159 

7.  Why  should  road  gravel  vary  in  size? 

8.  Why  is  it  best  not  to  use  too  large  pebbles? 

9.  What  is  common  binding  material? 

10.  How  much  binder  should  be  used? 

11.  Why  should  a  gravel  road  be  thoroughly  underdrained? 

12.  Describe  the  surface  method  of  constructing  gravel  roads. 

13.  What  thickness  of  gravel  is  usually  applied? 

14.  Describe  the  trench  method  of  constructing  gravel  roads. 

15.  How  much  do  gravel  roads  cost? 

16.  How  are  gravel  roads  maintained? 


CHAPTER  XXVi 
STONE  ROADS 

Stone  roads  include  all  roads  on  which  broken  stone  is 
used  as  the  principal  surfacing  material.  Stone  has  been 
used  in  road  construction  from  very  early  times,  where 
first-class  roads  were  desired. 

Telford  Roads.  Some  broken  stone  roads  are  given  the 
name  of  Telford,  when  they  incorporate  some  features  of 
road  construction  which  were  used  by  Mr.  Thomas  Telford, 
a  famous  English  engineer.  The  distinguishing  feature  of 
the  old  Telford  road  was  that  the  lower  course  or  layer  of 
stone  was  made  of  rather  large  flat  stones  laid  in  place  by 
hand.  At  the  present  time  any  road  which  uses  large  pieces 
of  material  in  the  base  or  lower  layer  may  be  called  a  Tel- 
ford road. 

Macadam  Road.  Most  stone  roads  which  have  been 
built  in  recent  years  follow  the  form  of  construction  proposed 
by  John  Loudon  McAdam,  another  famous  Enghsh  road 
engineer,  who  Hved  between  1756  and  1836.  So  general  is 
the  use  of  this  construction  that  it  has  become  customary  to 
call  all  broken-stone  roads  macadam  roads. 

Macadam  roads  are  made  of  broken  stone  throughout. 
The  stone  is  applied  in  three  or  more  layers,  and  in  the  usual 
construction  it  is  customary  to  place  the  larger  fragments  in 
the  lower  course. 

Road  Stone.  Not  all  kinds  of  stone  can  be  used  success- 
fully in  the  construction  of  stone  roads.  Good  road  stone 
must  be  hard  so  that  it  will  not  be  crushed  by  the  traffic 
which  will  come  upon  it.     It  must  also  be  hard  enough  to 

lliO 


ROADS 


161 


resist  wear,  which  requires  somewhat  different  character- 
istics from  the  abiUty  to  withstand  pressure.  Road  stone 
should  also  be  tough,  in  order  that  it  will  not  be  shattered 
by  the  blows  to  which  it  will  be  subjected.  It  must  also,  in 
the  usual  macadam  construction,  furnish  a  dust  which  has 
a  cementing  or  binding  power.  As  the  stone  wears,  a  dust 
forms,  which  becomes  lodged  between  the  stone  particles. 
This  dust  when  wet  forms  a  sort  of  cement  which,  upon 
hardening,  holds  the  fragments  of  stone  together,  resembling 
in  many  respects  cement  or  concrete. 

Testing  Stone  for  Road  Construction.  Nearly  every 
state  maintains  a  highway  commission  which  is  equipped  with 
apparatus  for  testing  road  stone  for  the  various  qualities 
mentioned.  These  tests  are  capable  of  determining  fairly 
and  accurately  just  what  may  be  expected  as  to  durability 
of  a  certain  kind  of  stone  when  used  in  road  construction. 
The  construction  of  stone  roads  is  so  expensive  that  in  no 
case  should  materials  of  doubtful  value  be  used. 


6— 


Fig.   84.     Rolling  the  first  course  of  stone. 


162 


AGRICULTURAL  ENGINEERING 


The  Construction  of  Stone  Roads.  As  usually  con- 
structed, the  stone  surfacing  in  a  country  road  is  made  from 
12  to  15  feet  wide.  The  stone  proper  is  usually  applied  in 
two  layers,  on  top  of  which  a  third  layer  of  stone  dust  or 
other  binding  material  is  used.  The  lower  course  is  usually 
made  from  23^  to  4  inches  thick,  and  the  upper  courses 
from  13/^  to  2  inches  thick.  Thus  the  total  thickness  of  the 
stone  varies  from  4  inches  to  6  inches  at  the  center  of  the 

road,  and  from  23^  inches 
to  4  inches  at  the  outer 
edge.  It  is  customary 
tc  apply  more  material 
in  the  center  of  the  road, 
where  the  wear  from 
traffic  is  the  greatest, 
than  at  the  outside. 

If  automatic  dump 
wagons  are  not  used  to 
spread  the  stone,  it  is 
generally  recommended 
that  it  be  applied  with 

Fig.  85.     Model  of  a  water-bound  macad-  shoVcls.       WhcU  StOUO  is 

am   road.     A   represents   the   prepared  sub-  ■,  i     •         i  j  v 

grade.     B   represents    the     first     course     of  dumped     m     UCapS,      the 

coarse     stone.       C    represents     the     second  i  p  x  11    x 

course  of  stone,  and  D  the  finishing  layer  larger    iragmeUtS   roll    tO 

of  stone,   chips  or  dust,      (Bui.  36,  Office  of  .i  ^    ^„  +  ^; J^    ^t    +U^     ^U^ 

Public  Roads,  u.  s.  Dept.  of  Agr.)  the  outside  01  the  pile 

and  the  finer  portion  is 
left  in  the  center.  The  stone  should  be  applied  in  layers  of 
uniform  thickness,  making  proper  allowance  for  the  shrink- 
age due  to  rolling.  The  packing  is  done  with  a  steam  roller. 
Horse  rollers  are  not  made  heavy  enough  for  this  purpose; 
the  ten-ton  traction  roller  is  the  size  in  general  use.  It  is 
customary  to  begin  the  rolling  at  the  outside  and  work 
toward  the  center.    After  the  lower  course  is  thoroughly 


ROADS  163 

packed  over  the  entire  width  of  the  road,  the  upper  courses 
may  be  applied.  This  consists  of  fragments  of  stone  which 
vary  in  diameter  from  13^  to  13^  inches.  After  being 
spread  in  a  manner  similar  to  that  described  for  the  lower 
course,  the  layer  of  binding  material,  which  usually  con- 
sists of  stone  screenings  and  dust,  is  applied.  This  is  usually 
about  1  inch  in  thickness  and  it  is  washed  down  into  the 
crevices  between  the  stone  as  much  as  possible  by  sprinkling. 
Rolling  is  continued  until  the  water  that  is  applied  in 
sprinkling  remains  on  the  surface.  No  more  binding 
material  should  be  used  than  is  necessary,  and  care  should 
be  used  to  leave  the  surface  of  the  road  as  smooth  and  in  as 
perfect  condition  as  possible.  After  rolling  and  bringing 
the  surface  into  proper  condition,  the  embankments  at  the 
sides  should  be  thoroughly  rolled  smooth  so  that  there  will 
not  be  any  unevenness  existing  between  the  stone  and  the 
side  ditches. 

Bituminous  Macadam  Roads.  The  construction  which 
has  just  been  described  has  been  the  standard  method  of 
stone  road  construction  for  many  years,  but  owing  to  a 
change  oi  traffic  other  forms  of  construction  have  come 
into  use,  and  this  construction  is  sometimes  designated  as 
"water-bound  macadam  roads."  It  has  proved  to  be 
highly  satisfactory  for  the  main  traveled  country  road, 
where  first-class  roads  are  desired  and  where  the  traffic 
is  Hmited  to  horse-drawn  vehicles.  The  automobile,  how- 
ever, has  introduced  a  new  problem  in  connection  with  road 
construction.  The  automobile  traveHng  at  a  high  speed 
with  its  broad  pneumatic  tire  sucks  out  from  between  the 
stone  fragments  the  dust  which  forms  the  binding  material, 
and  causes  the  stone  to  loosen,  or  "ravel,"  as  it  is  some- 
times described.  So  extensive  has  the  motor  traffic  become 
in  certain  localities,  that  not  only  must  steps  be  taken  to 


164 


AGRICULTURAL  ENGINEERING 


protect  the  macadam  roads  which  are  now  in  use,  but 
another  form  of  construction  must  be  adopted  for  new 
roads.  At  the  present  time  a  rather  large  number  of  mate- 
rials are  being  used  as  binders  experimentally.  One  class 
of  these  binders  is  known  as  bitumen,  which  includes 
not  only  the  natural  asphalt  products  but  also  similar 
material  obtained  from  gas  plants  in  the  nature  of  tars. 
In  addition  to  bitumen,  various  grades  of  oils  are  sometimes 
used  to  protect  roads.  Some  of  these  are  known  as  dust 
preventives. 

Method  of  Constructing  Bituminous  Macadam  Roads. 
There  are  two  general  methods  of  constructing  bituminous 

macadam  roads.  One  is 
known  as  the  penetration 
method,  and  the  other 
the  mixing  method.  In 
the  penetration  method, 
the  foundation  or  sub- 
grade  is  prepared  sub- 
stantially as  for  the 
water-bound  macadam 
road,  and  the  first  or 
second  layer  of  stone 
also  appHed  in  the  same 
way.     On    the    second. 

Fig.  86.     Model  of  a  bituminous  macadam  i 

road   made  by  the  penetration  method.     A  OT  Uppcr,  COUrSe  Or  layer, 

represents  the  prepared  sub-grade.     B  rep-  i  •.  •  1*    /^         + 

resents  the  first  course  of  stone,  and  C  the  DltUmen      IS     appUCQ      at 

second  course,     D  shows  the  first  applica-  „„    •^,,„   .«„  +  ^^      r,,r^v,^^v^«. 

tion  of  bitumin.    E  shows  the  application  various  ratcs,  averaging 

of  a  course  of  stone  chips.  F  shows  sec-  ..^ ^-V, „ r-vc.  1  1/  rroUr\-r»o  nav 
ond  application  of  bitumen.     G  shows   the    pemaps    1X2    g^^llOIlb    per 

Following 
this  a  layer  of  stone 
chips  is  applied,  and  then  another  layer  of  bitumen  at  the 
rate  of  perhaps  J^  gallon  per  square  yard. 


completed  road  with  a  layer  of  clean  stone  „„„„_„  iroT-rl 
chips,  lightly  rolled.  (Bui.  36,  Office  of  square  yaiU. 
Public  Roads,  U.  S.  Dept.  of  Agr.) 


ROADS  165 

In  the  mixing  method,  the  second  crust  or  layer  of  stone 
is  mixed  or  covered  with  bitumen  before  spreading.  This  is 
also  true  of  the  upper  layer  of  sand  or  chips,  which  is  thor- 
oughly mixed  with  bitumen  before  appl3dng  to  the  surface. 
It  is  expected  that  roads  of  this  type  will  largely  replace  the 
standard  or  water-bound  type. 

Cost  of  Stone  Roads.  The  cost  of  stone  roads  will  vary 
largely  with  the  cost  of  materials;  this  in  turn  being  directly 
dependent  upon  their  availability.  The  cost  in  different 
parts  of  the  United  States  varies  from  $1.20  to  $1.50  per 
square  yard,  and  from  $4000  to  $10,000  per  mile. 

Maintenance.  Macadam  roads  must  be  given  constant 
attention  or  they  will  be  rapidly  destroyed.  All  ruts  should 
be  quickly  filled  with  new  material  and  not  be  allowed  to 
become  larger.  After  several  years  of  wear,  depending 
upon  the  durabihty  of  the  materials  used,  it  will  be  neces- 
sary to  apply  a  new  layer  of  materials.  This  is  usually 
accompUshed  by  loosening  or  scarifying  the  surface,  leveling 
or  roUing  it  until  thoroughly  compact,  and  then  applying  new 
material  in  a  layer  two  or  three  inches  thick,  depending  upon 
the  condition  of  the  road.  This  repair  layer  is  applied  in  a 
way  similar  to  the  laying  of  the  second  course  in  the  original 
construction. 

Brick  Roads.  In  some  localities  where  stone  is  very 
expensive  or  where  good  durable  brick  may  be  obtained 
cheaply,  brick  roads  will  be  found  to  be  the  most  practical. 
In  the  construction  of  a  brick  road,  the  subgrade  or  foun- 
dation is  carefully  prepared  by  grading  and  rolUng,  and  the 
sides  of  the  road  are  provided  with  concrete  or  wooden 
curbs,  to  hold  the  brick  in  place.  On  the  subgrade  a  course 
of  stone  is  laid  and  thoroughly  rolled,  or  a  coarse  layer  of 
concrete  is  spread,  usually  about  6  inches  deep.  On  this 
course  a  layer  of  sand  is  spread  and  smoothed  as  a  cushion 


166  AGRICULTURAL  ENGINEERING 

on  which  the  brick  is  laid.  In  order  to  allow  for  the  expan- 
sion and  contraction  due  to  changes  of  temperature,  an 
expansion  joint  must  be  left  occasionally. 

Concrete  Roads.  Owing  to  a  reduction  in  th6  cost  of 
Portland  cement,  concrete  is  now  used  to  a  limited  extent 
in  the  construction  of  roads.  One  objection  to  concrete 
roads  is  that  they  are  slippery,  but  this  may  be  overcome. 
The  construction  of  concrete  roads  has  not  as  yet  become 
standardized. 

QUESTIONS 

1.  What  is  a  stone  road? 

2.  Describe  the  Telford  form  of  construction  for  stone  roads. 

3.  Describe  the  construction  of  the  macadam  road. 

4.  What  are  the  requisites  of  stone  for  road  construction? 

5.  Why  should  road  stone  be  tested? 

6.  Describe  the  construction  of  water-bound  stone  roads. 

7.  How  much  should  a  stone  road  be  rolled  at  the  finish? 

8.  Describe  two  methods  of  constructing  bituminous  macadaii? 
roads. 

9.  How  much  do  macadam  roads  cost  per  mile? 

10.  How  should  macadam  roads  be  maintained? 

1 1 .  Where  may  brick  roads  be  constructed  advantageously? 

12.  Describe  the  construction  of  brick  roads. 

13.  What  is  one  objection  to  the  concrete  road? 


CHAPTER  XXVII 


ROAD  MACHINERY 


Classes  of  Road  Machinery.  Road  machinery  may  be 
divided  into  two  general  classes,  those  used  in  building  roads 
and  those  for  the  maintaining  of  roads.  Although  machines 
in  the  first  class  may  be  used  in  connection  with  the  repairing 
of  roads,  there  are  a  few  machines  which  are  used  solely  for 
this  purpose.  There  is  a  rather  wide  variety  of  road 
machines,  and  it  is  not  possible  in  this  chapter  to  describe 
even  briefly  all  of  the  machines  which  might  be  considered. 

SCRAPERS,  ROLLERS,  ETC. 
Scoop  Scrapers.    One  of  the  most  simple  machines  used 

in  connection  with  road  construction  is  the  scoop  scraper,  or 

"slip."    This  scraper  is  simply 

a  large  scoop  arranged  with  a 

bail  for  drawing  and  handles  for 

dumping.    The  size  is  usually 

indicated  by  the  number   of 

cubic  feet  of  earth  the  scraper 

will  hold,  which  varies  from  3 

to  7.    The  cost   of   a  scoop 

scraper  varies  from  6  to  10  dollars.     The  scoop  scraper  is 

used  for  moving  earth  short  distances. 

Pole  or  Tongue  Scraper. 
The  pole  or  tongue  scraper  is 
used  in  leveling  the  road  sur- 
face. The  size  is  indicated  by 
the  width  in  inches,  and  the 
cost  varies  from  6  to  7  dollars. 

167 


Fig.    87.     Scoop   scraper   or   slip. 


Fig.    88.     Tongue   scraper. 


168 


AGRICULTURAL  ENGINEERING 


Fig.    89.     Buck  scraper. 


Buck  Scraper.  The  buck  scraper  is  sometimes  called 
the  Fresno,  and  is  used  extensively  in  irrigated  regions  in 
preparing  land  for  irrigation.  It  is  capable  of  being  adjusted 
to  spread  the  earth  in  a  layer  of  almost  any  thickness  when 

dumped.  These  scrapers  are 
made  3^,  4,  and  5  feet  wide, 
and  have  capacities  of  8,  10, 
and  12  cubic  feet,  respec- 
tively. 

The  Wheel  Scraper.  The 
wheel  scraper  consists  of  a 
steel  scoop  on  wheels  and  equipped  with  levers  for  raising 
and  lowering  and  for  dumping.  It  is  used  where  the  earth  is 
to  be  moved  some  distance, 
100  feet  or  more.  The  size  of 
this  scraper  is  usually  desig- 
nated by  numbers  1,  2,  and 
3,  which  have  the  capacities 
of  9,  12,  and  16  cubic  feet, 
respectively.  There  are  sev- 
eral grades  of  construction 
to  be  obtained.  If  the  haul, 
or  distance  the  earth  is  to  be 
moved,  is  great,  the  larger 
size  should  be  used,  even  if 
an  extra  team  or  *'snap  "  be  required  to  help  load  the  scraper. 
The  Scraping  Grader.  The  scraping  grader  is  the  princi- 
pal machine  used  in  the  construction  of  earth  roads.  It  con- 
sists usually  of  a  four-wheeled  truck,  with  a  wide  steel  blade 
mounted  underneath,  which  may  be  adjusted  to  almost  any 
angle.  The  standard  machine  requires  four  or  more  horses 
to  operate  it  successfully  in  average  soil.  A  lighter  or 
special  machine  is  made  which  can  be  used  for  repair  work. 


Fig.    90.      Wheel   scraper,    dumped. 


R0AD8  169 

and  is  often  used  with  two  or  four  horses.  In  addition  to  the 
machines  with  four-wheeled  trucks,  there  are  quite  a  number 
of  machines  on  the  market  in  which  attempts  are  made  to 
simphfy  the  construction,  and  also  to  reduce  the  cost.  The 
standard  scraping  grader  costs  from  $200  to  $250  at  the 
factory.  In  addition  to  the  usual  adjustments  provided 
for  setting  the  cutting  blade  to  any  angle  with  the  direction 
of  travel,  for  raising  and  lowering  either  end  and  giving  it 


any  desired  inclination  forward  or  backward,  the  wheels 
of  the  machine  are  made  to  follow  in  the  furrows  of  the  blade, 
or  may  be  adjusted  at  such  an  angle  as  to  resist  the  side 
thrust  due  to  using  the  blade  at  an  angle  with  the  direction 
of  travel.  The  use  of  the  scraping  grader  is  quite  simple, 
but  much  skill  may  be  obtained  by  experience.  In  using  a 
machine  it  is  customary  to  plow  a  furrow  at  the  side  of  the 


170 


AGRICULTURAL  ENGINEERING 


road  where  the  side  ditch  is  to  be  located,  using  one  corner 
of  the  blade.  The  earth  from  this  furrow  is  then  scraped  to 
the  center  of  the  road  and  spread  by  the  grader. 

Elevating  Graders.  The  elevating  grader  is  a  compli- 
cated machine  in  many  respects.  It  is  provided  with  a  four- 
wheel  carriage  and  a  plow  that  is  operated  at  one  side.  An 
endless  apron  driven  by  power  from  the  rear  truck-wheels 
receives  the  earth  from  the  plow  and  elevates  and  discharges 
it  either  in  the  center  of  the  road  or  into  wagons  drawn 
beside  the  grader.  These  machines  may  be  operated  either 
by  horses  or  by  traction  engines.  The  standard  machine 
requires  12  horses,  eight  in  front  and  four  behind.     This 


Fig.  92.     An  elevating  grader. 


machine  will  grade  a  new  earth  road  in  good  soil  at  the  rate 
of  a  quarter  of  a  mile  per  day,  where  the  width  does  not 
exceed  thirty  feet  and  where  a  crown  of  twelve  inches  at 
the  center  is  made.  Elevating  graders  vary  somewhat  in 
size  and  weight. 

Horse  Rollers.  Horse  rollers  for  road  construction  con- 
sist essentially  of  a  large  cast-iron  drum  with  a  frame  and 
tongue  for  drawing.     They  are  usually  made  4  to  6  feet  wide 


ROADS  171 

and  weigh  from  3  to  6  tons.  To  overcome  the  difficulty  of 
turning  the  roller  about,  a  tongue  with  a  wheel  truck  is 
attached  to  a  yoke  which  is  pivoted  directly  over  the  center 
of  the  roller  drum,  and  which  may  be  unlatched  from  one 
side  and  turned  about  to  the  opposite  side  and  latched, 
enabling  the  drum  to  be  drawn  in  the  reverse  direction  with- 
out turning.  Rollers  made  of  cast-iron  cost  about  $100  per 
ton  of  weight.  Cheaper  rollers  are  made  by  building  up 
the  hollow  drum  of  cast  iron  or  steel  plate,  and  filling  with 
water  or  concrete.  In  the  construction  of  stone  roads  it  is 
highly  essential  that  a  heavy  roller  be  used,  and  for  this 
reason  the  horse  roller  is  seldom  used. 

Power  Rollers.  The  steam  roller  is  of  two  types — one 
known  as  the  three-wheel  roller  and  the  other  as  the  tandem 
roller.  The  three-wheel  roller  resembles  the  traction  engine, 
in  which  the  guide  wheels  are  replaced  with  a  rolling  drum 
and  the  drivewheels  have  smooth  treads.  Gasoline  and  oil 
engines  are  being  substituted  for  steam  power  for  rollers 
to  some  extent.  Many  traction  engines  are  made  so  as  to  be 
easily  equipped  in  this  way.  The  weight  of  these  rollers 
varies  from  10  to  20  tons  and  the  pressure  under  the  drivers 
will  vary  from  450  to  650  pounds  per  inch  of  width. 

Tandem  rollers,  sometimes  called  asphalt  rollers,  con- 
sist of  two  rolling  drums  at  the  ends  of  a  frame.  Most  of  the 
weight  is  applied  to  one  of  these  drums,  which  is  driven  by 
power  from  a  steam  or  a  gasoline  engine,  and  the  other  is 
used  for  guiding.  This  type  of  roller  tends  to  leave  the  sur- 
face smoother  than  the  three-wheel  type,  but  cannot  be 
handled  quite  as  conveniently  over  country  roads.  Although 
it  can  be  used  for  drawing  other  machines  it  is  not  used  so 
extensively  in  this  connection  as  the  three-wheel  type.  It 
cannot  be  provided  with  spikes  for  loosening  old  road  sur- 
faces preparatory  to  resurfacing. 


172 


AGRICULTURAL  ENGINEERING 


Rock  Crushers.  One  of  the  essential  machines  in  con- 
nection with  the  building  of  a  stone  road  is  the  rock  crusher 
for  reducing  stones  to  fragments  of  the  proper  size.  Usually 
these  crushers  are  located  at  the  quarry,  and  the  stone  is 
shipped  ready  for  application  to  the  road. 


Fif 


Stone    crushing-    plant.      A    thrfe-wheeled    steam    roller    and 
dump  wagon  are  shown  in   the  foreground. 


Other  Machinery.  The  equipment  necessary  for  build- 
ing stone  roads  includes  several  other  machines.  Among 
these  may  be  mentioned  screens  for  grading  the  stone,  dump 
wagons  for  hauling  and  spreading  the  stone,  and  sprinklers 
for  applying  water  or  binding  material  in  the  form  of  a 
liquid.  When  old  roads  are  to  be  repaired,  plows  or  scari- 
fiers, which  are  heavy  tools  with  cultivator-shaped  teeth  for 
breaking  up  the  surface,  are  necessary. 


ROADS  173 

MACHINES  FOR  MAINTAINING  ROADS 

Road  Drags.  The  principal  machine  for  maintaining 
roads  of  all  kinds  is  the  road  drag.  As  devised  by  Mr.  D. 
Ward  King  this  consists  of  two  planks  or  halves  of  a  split 
log,  about  8  feet  long,  and  held  about  30  inches  apart  with 
braces.  These  planks  are  so  placed  that  one  will  follow 
the  other  when  drawn  at  an  angle  of  45  degrees  with  the 
direction  of  travel.  The  front  plank  is  usually  shod  with  a 
steel  blade  for  about  one-half  its  length,  which  resists  the 


Pig.   94.     Road  drags  made  of  plank  and  split  log. 

wear  and  enables  the  drag  to  have  more  effect  upon  the  sur- 
face. Two  chains  are  provided,  one  from  each  end  of  the 
drag,  which  are  of  such  length  as  to  give  the  drag  the  desired 
inclination  with  the  direction  of  travel. 

It  has  been  found  that  the  drag  works  best  with  the  longer 
chain  passed  over  the  plank,  and  the  shorter  chain  attached 
near  the  middle  of  the  short  plank  close  to  one  end.  There 
are  many  other  types  of  drag  to  be  found  in  use.  One  is 
known  as  the  V  drag,  which  is  designed  to  cover  the  entire 
width  of  the  road  surface  at  a  time.  There  are  also  several 
types  of  road  drags  made  of  angles  or  bars  of  steel  in  place  of 
the  planks  of  the  King  drag. 


174  AGRICULTURAL   ENGINEERING 

QUESTIONS 

1.  For  what  may  the  scoop  scraper,  or  sUp,  be  used? 

2.  What  are  the  special  uses  of  the  tongue  and  buck  scrapers? 

3.  Describe  the  construction  of  the  wheel  scrapers. 

4.  Why  is  it  economical  to  use  large  sizes  where  the  haul  is  long? 

5.  Describe  the  work  of  the  scraping  grader. 

6.  Describe  the  construction  of  the  elevating  grader. 

7.  What  is  the  usual  weight  of  horse  rollers? 

8.  Describe  two  types  of  steam  rollers. 

9.  What  are  some  of  the  machines  required  for  the  building  of 
stone  roads  not  mentioned  above? 

10.  Describe  the  construction  of  a  road  drag  of  plank  or  split  logs. 


CHAPTER  XXVIII 
CULVERTS  AND  BRIDGES 

Importance  of  Culverts  and  Bridges.  A  large  proportion 
of  the  cost  of  maintaining  the  highways  of  the  country  is 
used  in  the  construction  of  culverts  and  bridges.  Not  only 
is  it  desirable  that  the  money  thus  expended  be  used  in  such 
a  way  as  to  secure  the  best  results,  but  faulty  construction 
should  be  guarded  against  on  account  of  the  risk  of  life  to 
those  who  must  pass  over  them  with  heavy  loads.  To 
secure  economy  it  is  necessary  that  bridges  and  culverts  be 
intelligently  and  economically  designed,  and  that  they  be 
made  of  durable  and  permanent  material.  Recent  changes 
in  road  traffic  demand  that  there  shall  be  advancement  in 
the  designing  and  constructing  of  culverts  and  bridges,  in 
order  that  the  heavier  loads  which  bridges  are  now  called 
upon  to  bear  shall  be  carried  without  risk  of  failure. 

Design  of  Culverts  and  Bridges.  The  designing  of  cul- 
verts and  bridges  should  be  placed  in  the  hands  of  a  skilled 
engineer,  who  will  be  able  to  proportion  the  structure 
properly.  The  practice  in  certain  locahties  of  making  appro- 
priations of  public  funds  for  bridges  without  first  securing 
from  one  who  has  had  experience  an  estimate  of  the  cost  of  a 
bridge  to  fill  the  requirements  of  the  conditions  to  be  met 
may  be  justly  criticised. 

Size.  The  first  feature  in  the  consideration  of  a  culvert 
is  the  determination  of  the  size  required.  Highway  engineers 
have  reported  that  culverts  are  often  not  properly  propor- 
tioned to  the  needs  to  be  met,  being  either  too  large  or  too 
small.     The  area  of  a  cross-section  of  a  culvert  or  bridge 

175 


176 


AGRICULTURAL  ENGINEERING 


should  vary  with  the  amount  of  water  which  must  pass 
through  it.  Some  engineers  use  Kutter's  formula,  given 
in  the  chapter  on  land  drainage.  To  determine  the  required 
area  of  the  cross-section  of  a  culvert,  a  more  simple  formula 


Fig.    95.     Making   a    concrete    culvert. 


has  been  proposed  by  Professor  A.  N.  Talbot,  of  the  Uni- 
versity of  Illinois.  Professor  Talbot  states  that  the  formula 
is  to  be  used  as  a  guide  to  judgment.     It  is  stated  as  follows: 


ROADS 


177 


The  area  of  waterway  in  square  feet  should  equal 


C  X 


4. 
1/ 


(drainage  area  in  acres)  ^ 


in  which  C  is  a  coefficient  and  will  vary  from  /^  to  1,  the  larger 
value  being  used  where  the  slopes  are  steep  and  the  ground  is 
broken.  The  4th  root  of  the  quantity  under  the  radical  may 
be  obtained  by  extracting  the  square  root  of  the  square  root. 

Foundation.  Many  bridges  fall  because  they  are  not 
placed  upon  a  proper  foundation.  Great  care  should  be  used 
to  see  that  solid  earth  which  will  not  be  undermined  by  water 
is  available  for  the  smaller  bridges.  For  larger  bridges  the 
foundation  should  be  placed  on  solid  rock,  if  possible;  and 
where  this  can  not  be  done,  piling  and  other  methods  of 
providing  large  surface  for  the  foundation  should  be  used. 

Concrete  Culverts  and  Bridges.  Perhaps  there  is  no 
purpose  to  which  concrete  made  of  Portland  cement  can  be 
put  to  better  use  than  in  the  construction  of  culverts  and 


M 


A  Caf  Barj  /♦  /onj 


ULL  ■  IOC tta  pef  i^ fr 
C  LI    ■  20/»m  . 

OL    sotiupva^n 


^C«rrO»rj  i*   CloC 


rmai.e  Of  oiMnr 

TlCi 

'-   urisr 

^ce^t^S'* 

f«««-,r-J«7r,/r 

It  Cy  Ft 

/■fjtfflie 

A-«-.    "  fsTet^ 

ot,a^ 

J«*            \,tcm 

oooc»yti 

««.*«,•  ^»». 

o,t 

e«rr  aart^-so  CO  Ban 

S  Ofrs 

STanoAQD  DCSlOn 

z-FT^z-nao^uL  year 


Fig.   96.     Plans  and  table  of  materials   for  reinforced  concrete  culvert. 


178 


AGRICULTURAL  ENGINEERING 


bridges.  Stone  and  brick  make  desirable  culverts,  but  the 
convenience  of  handling  and  reinforcing  concrete  with  steel 
makes  it  very  useful  for  culvert  and  bridge  construction. 
Vitrified  Pipe  and  Steel  Pipe  Culverts.  Vitrified  clay 
pipes  or  sewer  pipes  are  used  extensively  for  small  culverts, 
and  are  quite  satisfactory  when  covered  with  a  sufficient 

amount  of  earth.  It 
is  desirable,  however, 
that  the  ends  be  pro- 
tected with  wing  walls 
made  of  masonry. 
Steel  or  iron  pipes  are 
used  to  a  considerable 
extent;  but  owing  to 
the  thinness  of  the 
metal  in  most  cases, 
they  are  regarded  as 
of  questionable  merit. 
Cast-iron  pipes  are 
regarded  as  quite 
satisfactory,  but  are 
expensive. 

The  Work  of  State 
Highway  Commis- 
sions. The  majority  of  states  now  have  a  highway  com- 
mission or  a  highway  engineer,  whose  function  is  to  furnish 
standard  plans  and  specifications  for  culverts  and  bridges.  It 
is  advised  that  these  plans  and  specifications  should  be  used 
in  all  cases.  Besides  representing  the  most  improved  design, 
they  enable  the  work  to  be  let  by  contract  in  a  highly  satis- 
factory way.  All  features  of  the  construction  will  be  clearly 
defined  as  to  quantity  and  quality  in  the  plans  and  specifi- 
cations furnished  by  these  officers. 


97.     Concrete    culvert    after    the    plan    of 
Fig.    96. 


ROADS 


179 


Large  Bridges.     All  large  bridges  should  be  designed  and 
their  construction  supervised  by  a  skilled  engineer.     In  the 


Fig.   98.     A  concrete   bridge   which   failed  on  account  of  the  foundation. 

majority  of  states  the  state  highway  commission  is  in  a  posi- 
tion to  furnish  such  an  engineer. 


QUESTIONS 

1.  Why  should  culvert   and  bridge  construction   receive   careful 
consideration? 

2.  What  should  be  considered  in  selecting  a  culvert   or  bridge? 

3.  What  should  govern  the  size  of  the  culvert? 

4.  Why  is  it  important  to  have  good  bridge  foundations? 

5.  Why  is  concrete  a  good  material  for  culverts  and  bridges? 

6.  What  are  the  merits  of  metal  culverts? 

7.  What  is  the  work  of  the  State  Highway  Commission? 

REFERENCE  TEXTS 

Roads  and  Pavements,  by  I.  O.  Baker. 

Highway  Construction,  by  Austin  T.  Byrne. 

A  Text-book  on  Roads  and  Pavements,  by  Frederick  P.  Spaulding. 

Bulletins  of  the  Office  of  Public  Roads,  U.  S.  Depart,  of  Agric. 


PART  FIVE— FARM  MACHINERY 


CHAPTER  XXIX 
FARM  MACHINERY  AND  AGRICULTURE 

Introduction  of  Farm  Machinery.  Farming,  or  the  culti- 
vation of  the  soil  to  obtain  a  sustenance,  was  a  recognized 
occupation  even  before  the  time  history  was  first  written. 
For  ages,  however,  there  was  little  development  in  farm 
machinery.  Until  the  beginning  of  the  last  century  nearly 
all  the  work  of  the  farm  was  performed  by  the  aid  of  crude 
hand  tools.  The  number  of  horse-  or  animal-drawn  imple- 
ments or  machines  that  had  been  developed  were  few. 

Although  hand  tools  were  used  almost  exclusively  for 
thousands  of  years,  when  the  application  of  power  other  than 
man  power  to  the  work  of  the  farm  began,  the  development  of 
machinery  was  very  rapid.  In  the  Twelfth  Census  Report  it 
is  stated,  "The  year  1850  practically  marks  the  close  of  the 
period  in  which  the  only  farm  implements  and  machinery 
other  than  the  wagon,  cart,  and  the  cotton  gin,  were  those 
which,  for  want  of  better  designation,  might  be  called  imple- 
ments of  hand  production.''  In  the  early  part  of  the  nine- 
teenth century  the  grain  was  cut  with  the  sickle  or  cradle 
and  bound  by  hand.  It  was  threshed  by  beating  with  the 
flail  or  by  the  treading  of  animals.  The  plow  was  a  crude 
affair,  usually  homemade  and  shod  with  iron  by  the  village 
blacksmith,  and  the  principal  tool  for  cultivation  was  the 
hoe.  A  cast-iron  plow  was  first  made  by  Charles  Newbold, 
of  New  Jersey,  sometime  between  1790  and  1796,  and  John 

180 


FARM  MACHINERY  181 

Deere  made  his  first  steel  plow  in  1833.  Patents  on  the 
reaper  were  granted  to  Obed  Hussey  in  1833  and  to  Cyrus 
W.  McCormick  in  1834.  The  two-horse  cultivator  was  first 
used  about  1861.  The  first  patent  on  a  drill  granted  to  an 
American  was  in  1799,  but  the  force  feed  for  a  drill  was  not 
patented  until  1851.  The  first  patent  on  a  corn  planter 
came  in  1839. 

These  machines  did  not  come  into  general  use  until  many 
years  after  the  date  of  the  first  patents.  The  old  men  of 
to-day  can  remember  the  hand  methods  which  prevailed 
throughout  the  country  during  their  boyhood  and  young 
manhood.  The  opening  of  large  areas  of  rich  agricultural 
land  to  settlement  in  the  United 
States  during  the  middle  of  the 
century,  followed  by  the  scarcity 
of  workers  caused  by  the  Civil 
War,  were  no  doubt  the  im- 
portant  influences    in    bringing     ^,     ^^    ^^     ,  , ,       ^  ^^ 

^  ^         ,  .  Fig.    99,     The  sickle  and  the 

about     a     rapid     introduction    of    cradle.  hand  tools  for  harvest- 
farm  machinery. 

The  influence  of  the  introduction  of  farm  machinery  on 
agriculture  has  been  stupendous  and  far-reaching.  Some  of 
the  direct  effects  produced  will  now  be  set  forth. 

Change  in  Farm  Labor.  When  hand  methods  prevailed, 
the  labor  of  the  farm  was  performed  largely  by  slaves  or  the 
cheapest  form  of  labor.  From  the  beginning,  the  cultiva- 
tion of  the  soil  has  been  synonomous  with  deadening  toil 
and  drudgery.  The  introduction  of  farm  machinery  has 
changed  this  entirely,  a  fact  which  is  emphasized  by  the  com- 
parison of  the  harvesting  of  grain  with  a  modern  self-binding 
harvester  with  the  old  method  of  cutting  with  the  sickle  or 
cradle  and  binding  by  hand;  or  the  threshing  of  grain  with 
a  modern  threshing  machine    equipped  with   self-feeder, 


182  AGRICULTURAL  ENGINEERING 

weigher,  and  wind  stacker  compared  with  the  threshing  of 
grain  with  a  flail. 

A  poet  once  wrote  of  the  agricultural  laborer  as  the  ''man 
with  the  hoe,  stolid  and  stunned — a  brother  to  the  ox." 
Contrast  this  condition  with  that  of  the  operator  of  a  modern 
machine  like  a  gang  plow,  a  harvester,  or  a  two-row  culti- 
vator, where  no  effort  is  required  beyond  the  direction  of  the 
energy  of  the  horses  and  the  adjusting  of  the  machine. 
J.  R.  Dodge,  in  the  Report  of  the  Industrial  Commission, 
1901,  wrote,  ''As  to  the  influence  of  machinery  on  farm 
labor,  all  intelligent  expert  observation  declares  it  benefi- 
cial. It  has  relieved  the  laborer  of  much  drudgery;  made  his 
work  easier  and  his  hours  of  service  shorter;  stimulated  his 
mental  faculties;  given  an  equilibrium  of  effort  to  mind  and 
body;  and  made  the  laborer  a  more  efficient  worker,  a  broader 
man,  and  a  better  citizen."  It  is  doubtful  if  Arming  would 
appeal  at  all  to  the  young  men  of  to-day  if  there  had  not  been 
a  change  from  hand  methods  to  machine  methods. 

Length  of  Working  Day.  The  working  day  has  been 
materially  shortened  since  the  introduction  of  labor-saving 
machinery.  The  capacity  of  the  worker  was  so  limited  with 
hand  methods  that  it  was  necessary  to  work  to  the  limit  of 
endurance  when  crops  demanded  it. 

Increase  in  Wages.  There  has  been  a  very  marked 
increase  in  wages  with  the  introduction  of  farm  machinery; 
and  although  this  is  true  of  all  occupations,  farm  machinery 
has  undoubtedly  been  a  factor  in  bringing  about  the  increase. 
A  farm  worker  can  earn  more  by  working  with  a  machine 
than  by  hand;  however,  a  comphcated  machine  requires 
greater  skill  for  its  successful  operation.  It  was  thought 
by  many  at  the  time  machinery  was  being  generally  intro- 
duced that  wages  would  be  decreased,  owing  to  the  fact  that 
some  workers  would  be  displaced  with  machines.     In  the 


FARM  MACHINERY  183 

United  States,  in  1849,  the  average  wages  of  a  farm  worker 
did  not  exceed  $120  a  year.  In  countries  where  machinery 
is  used  Httle  at  the  present  time,  wages  are  very  low. 

Labor  of  Women  in  Fields.  When  hand  methods  pre- 
vailed, the  labor  of  women  was  required  in  the  fields  to  care 
for  the  crops  during  the  seasons  when  they  required  urgent 
attention.  Now  the  services  of  women  are  seldom  required 
in  the  field,  and  in  addition  many  machines  have  been 
devised  to  aid  her  in  the  housework.  Again,  much  of  the 
work  formerly  required  of  her  in  the  home,  like  spinningj 
weaving,  garment  making,  soap  making,  and  candle  making 
have  been  transferred  to  the  factory,  where  machinery  may 
be  economically  used  in  the  work. 

Percentage  of  Population  on  Farms.  The  percentage  of 
the  total  population  living  on  farms  in  the  United  States  has 
decreased  continually  since  1800.  At  that  time  97  per  cent 
of  the  people  lived  on  farms;  in  1849  the  percentage  had 
decreased  to  90  per  cent,  and  in  1899  only  35.7  per  cent  of  the 
people  lived  on  farms. 

Increase  in  Production.  Notwithstanding  the  decrease 
in  the  farm  population  in  this  country,  the  production  of 
agricultural  products  per  capita  has  increased.  In  1800, 
5.50  bushels  of  wheat  were  produced  per  capita;  in  1849, 
4.43  bushels;  in  1880,  9.16  bushels;  in  1890,  7.48  bushels; 
and  in  1900,  8.66  bushels  per  capita.  The  production  of 
corn  per  capita  increased  from  25.53  bushels  in  1850  to  34.94 
bushels  in  1900. 

Cost  of  Production.  The  cost  of  producing  farm  crops 
has  been  materially  lowered,  although  the  cost  of  labor  has 
increased  many  fold.  It  is  stated  by  one  authority  that  the 
average  cost  of  producing  farm  crops  was  reduced  50  per 
cent  from  1850  to  1895.  This  reduction  of  cost  is  largely 
due  to  a  reduction  in  the  time  required  in  production.     In 


184  AGRICULTURAL  ENGINEERING 

the  thirteenth  annual  report  of  the  Department  of  Labor  it 
is  stated  that  the  amount  of  labor  required  to  produce  a 
bushel  of  wheat  by  hand  methods  was  3  hours  and  3  minutes, 
and  by  machine  methods  this  has  been  reduced  to  ten  min- 
utes. In  the  1899  Yearbook  of  the  Department  of  Agricul- 
ture it  is  reported  that  the  average  time  of  labor  required  to 
cut  and  cure  a  ton  of  hay  has  been  reduced  from  11  hours  to 
1  hour  and  39  minutes. 

Quality  of  Products.  The  quality  of  farm  products  has 
been  materially  influenced  by  the  introduction  of  farm 
machinery  which  enables  the  farmer  to  harvest  his  crop  at 
the  best  time.  For  instance,  when  hand  methods  prevailed 
it  was  customary  to  begin  the  harvesting  of  small  grain 
before  it  was  properly  ripened,  and  the  harvesting  was  con- 
tinued past  the  time  the  grain  was  in  the  best  condition, 
resulting  in  shrunken  and  damaged  grain.  The  crops  are 
generally  cleaner  and  more  uniform  now  than  under  the 
methods  prevailing  three  quarters  of  a  century  ago.  It 
would  be  difficult  now  to  induce  people  to  eat  bread  made 
from  wheat  threshed  by  the  treading  of  animals. 

Income  of  Farm  Workers.  A  study  of  the  Census 
report  of  the  income  of  farm  workers  in  the  different  states 
and  the  average  investment  in  farm  machinery  indicates 
that  the  income  varies  almost  directly  with  the  amount  of 
machinery.!  The  following  table  contains  only  the  extreme 
cases  given  in  the  report. 

G.  F.  Warren  and  K.  C.  Livermore,  of  Cornell  University, 
in  reporting  an  agricultural  survey  made  in  Tompkins 
County,  New  York  State,  say,  "In  each  of  the  groups  [refer- 
ring to  size  of  farms]  the  farmer's  labor  income  is  almost  the 
same  as  the  value  of  his  machinery."    These  observations 


1 S.  A.  Knapp,  of  the  United  States  Department  of  Agriculture,  has  reported 
data  from  the  census  report,  in  Circular  21,  Bureau  of  Plant  Industry. 


FARM  MACHINERY 


185 


Influence  of  farm  machinery  on  income. 


State 

Annual  income  of  each 
worker 

Value  of  ma- 
chinery and  im- 
plements for 
each  farm 

Florida 

Alabama 

$119.72 
143.98 
611.11 
755.62 

$  30.43 
23.40 

Iowa 

196.55 

North  Dakota 

238.84 

are  sufficient  to  indicate  clearly  that  farm  machinery  is  an 
important  factor  in  modern  farming  operations  and  that  an 
agricultural  student  who  intends  to  make  the  farm  the  object 
of  his  life  work  will  do  well  to  give  a  careful  study  of  the 
subject  of  machinery. 

QUESTIONS 

1.  Explain  some  of  the  causes  which  brought  about  a  rapid  de- 
velopment of  agricultural  machinery  in  America. 

2.  What  were  the  hand  tools  used  in  harvesting  and  cultivation? 

3.  What  effect  has  the  use  of  machinery  had  on  farm  labor? 

4.  Has  the  length  of  the  working  day  changed  since  the  introduc- 
tion of  farm  machinery?  Explain. 

5.  How  have  wages  changed  since  the  time  of  hand  production? 

6.  Show  how  machinery  has  changed  the  work  of  women. 

7.  Explain  how  production  of  some  of  the  principal  crops  per  capita 
in  the  United  States  has  changed,  and  also  explain  the  changes  in  the 
percentage  of  the  population  living  on  farms. 

8.  How  has  the  cost  of  production  changed  with  the  introduction 
of  machinery? 

9.  What  effect  has  machmery  upon  the  quality  of  products? 

10.  What  is  the  ratio  between  the  amount  invested  in  farm  ma- 
chinery in  the  various  states  and  the  average  income  of  the  farm 
workers? 

Note:  The  student  should  study  the  development  of  farm 
machinery  by  consulting  the  older  residents  in  the  community  in  regard 
to  the  methods  in  vogue  during  their  lifetime.  A  study  should  also 
be  made  of  the  cost  of  doing  work  by  different  existing  methods. 


CHAPTER  XXX 
DEFINITIONS  AND  PRINCIPLES 

A  Tool.  A  tool  is  an  instrument  such  as  a  hammer,  fork, 
or  spade  used  in  performing  manual  operations.  Tools  so 
defined  will  not  be  discussed  in  this  text.  The  term  may  be 
used,  perhaps  incorrectly,  to  designate  a  machine  or  an  imple- 
ment. Machines  for  making  hay,  for  instance,  are  some- 
times called  hay  tools. 

Implements.  The  term  implement  is  applied  to  both 
tools  and  machines.  A  dealer  in  these  wares  is  generally 
known  as  an  implement  dealer. 

Machines.  A  machine  is  any  device  consisting  of  two 
or  more  parts  arranged  to  modify  forces  and  motions,  to 
produce  a  desired  effect  or  do  some  useful  work.  Machines 
require  energy  from  an  outside  source  to  drive  or  operate 
them,  and  of  this  energy  a  part  is  required  to  drive  the 
machine  itself  and  a  part  is  required  to  do  the  useful  work. 
As  will  be  explained  later  this  energy  is  generally  designated 
as  work.  The  ratio  between  the  work  put  to  any  useful  end 
and  the  total  amount  of  work  given  to  the  machine  is  known 
as  the  efficiency  of  a  machine.  For  instance,  suppose  that 
a  certain  machine,  like  a  pump,  requires  one  horsepower  of 
energy  to  operate  it.  Suppose  that  of  this  amount,  one- 
half  horsepower  is  used  in  the  actual  lifting  of  the  water 
and  the  remainder  is  used  in  overcoming  the  friction  in  the 
pump.    Then  the  efficiency  of  the  pump  is  50  per  cent. 

Elements  of  Machines.  All  machines,  regardless  of  their 
intricacy,  may  be  reduced  to  the  elements  of  machines,  or 
the  simple  machines,  as  they  are  called.    These  comprise 

ISO 


FARM  MACHINERY  187 

the  fundamental  devices  for  modifying  forces  and  motions. 
They  are  six  in  number,  and  are  the  lever,  the  wheel  and  axle, 
the  inchned  plane,  the  screw,  +he  wedge,  and  the  pulley. 

Essentials  of  a  Machine.  Any  machine  to  be  satisfac- 
tory must  fulfil  at  least  four  requirements.  First,  it  must  do 
the  work  required  of  it  satisfactorily;  for  instance,  a  har- 
vester must  cut  the  standing  grain  and  bind  it  into  bundles 
with  never-failing  accuracy.  Second,  the  machine  must  do 
its  work  efficiently;  that  is,  it  must  require  Uttle  power  to 
drive  it,  as  in  the  case  of  horse-drawn  machines,  where  the 
draft  must  be  low.  Third,  the  parts  of  the  machine  must  be 
strong  enough  to  resist  breakage.  Fourth,  the  machine 
must  be  so  designed  as  to  be  durable,  or  able  to  resist  wear; 
such  parts  that  are  subject  to  wear  should  be  capable  of 
adjustment  or  replacement. 

The  first  two  of  these  requirements  demand  proper  con- 
struction on  the  part  of  the  machine  and  skillful  adjustment 
and  management  on  the  part  of  the  operator.  The  number 
of  farm  machines  now  manufactured  is  very  large,  and  in 
most  cases  there  are  several  types  and  sizes  of  a  machine  for 
each  kind  of  work.  Each  machine  will  do  its  best  work  and 
render  the  best  service  when  used  under  the  conditions  for 
which  it  is  made  to  work.  The  part  of  this  text  devoted  to 
farm  machinery  is  planned,  in  the  main,  to  give  instruc- 
tion in  the  selection,  adjustment,  and  operation  of  the  various 
farm  machines  required  in  general  farm  practice.  In  addi- 
tion, tliere  will  be  a  discussion  of  the  principles  involved  in 
the  strength  and  durability  of  a  machine. 

Friction.  As  a  machine  operates,  there  must  be  at  cer- 
tain points  a  sliding  of  one  surface  over  another.  It  matters 
not  how  carefully  the  'surfaces  may  be  prepared  there  is 
always  some  resistance  to  the  sliding,  which  resistance  is 
known  as  friction.    The  magnitude  of  this  resistance  in 


188  AGRICULTURAL  ENGINEERING 

friction  varies  much  with  conditions  and  it  is  desirable  in 
most  instances  to  keep  it  as  small  as  possible,  as  it  is  a  waste 
of  energy  or  power  and  lowers  the  efficiency  of  the  machine. 
There  are  instances  where  friction  is  highly  essential,  as  in 
the  case  of  the  transmission  of  power  by  means  of  a  belt,  or 
the  use  of  friction  in  the  friction  clutch  in  engaging  a  part  at 
rest  with  a  revolving  part.  The  shoes  of  the  clutch  slip 
when  first  engaged,  allowing  the  parts  at  rest  to  attain  speed 
slowly,  thus  relieving  the  machine  of  severe  shocks,  but 
finally  they  furnish  enough  resistance  to  shpping  to  transmit 
the  full  power  of  the  machine.  The  ratio  between  the  force 
holding  the  two  surfaces  together  and  the  force  necessary  to 
sHp  one  surface  over  the  other  is  called  the  coefficient  of 
friction.  Thus  if  a  body  weighing  10  pounds  requires  a  hori- 
zontal force  of  1  pound  to  move  it  over  a  level  surface,  then 
the  coefficient  of  friction  equals  .1.  In  most  instances  it  is 
desirable  to  keep  the  coefficient  of  friction  as  low  as  possible, 
which  is  done  by  making  the  sUding  parts  of  the  machine  of 
materials  which  give  a  low  coefficient  of  friction,  and  by 
applying  a  lubricant  between  the  surfaces. 

When  two  surfaces  in  contact  are  at  rest  for  a  time  they 
seem  to  interlock,  so  that  a  greater  force  is  required  to  cause 
them  to  start  to  sHde  over  each  other  than  to  continue  the 
movement  after  sliding  begins.  The  friction  of  rest  is  there- 
fore greater  than  the  friction  of  motion. 

Rolling  Friction.  When  a  body  with  a  circular  cross- 
section  is  rolled  over  a  plane  surface,  some  resistlStnce  is 
offered,  but  not  as  much  as  in  the  case  of  sliding.  This 
resistance  is  due  to  a  compression  or  indentation  of  the  sur- 
faces in  immediate  contact;  hence  rolling  friction  is  less  with 
•hard  bodies.  Since  rolhng  friction  is  so  much  less  than 
sliding  friction,  rollers  are  often  inserted  between  two  sur- 
faces which  would  otherwise  slide  over  each  other. 


FARM  MACHINERY  189 

Lubrication.  To  reduce  friction  between  two  sliding  sur- 
faces and  to  reduce  the  wear  and  heating,  it  is  common 
practice  to  apply  some  substance  which  will  adhere  to  each 
of  the  surfaces  in  a  thin  layer,  smoothing  them,  and  pre- 
venting them  from  coming  in  such  close  contact.  Such  a 
substance  is  called  a  lubricant.  The  friction  really  takes 
place  between  two  surfaces  of  the  lubricant. 

Oils  and  greases  are  generally  used  as  lubricants. 
Graphite,  which  is  carbon  in  a  very  finely  divided  state,  is 
often  used  in  connection  with  oils,  and  has  the  property  of 
smoothing  the  surfaces.  Mica  finely  divided  is  used  in  the 
same  way  in  axle  grease. 

Choice  of  a  Lubricant.  It  is  desirable  that  lubricating 
oil  be  as  light  and  thin  as  possible,  and  still  heavy  enough, 
or  having  enough  ''body,"  to  prevent  being  squeezed  out 
from  the  surfaces  in  contact.  Heavy  oils  and  grease,  being 
more  viscous,  give  a  higher  coefficient  of  friction,  and  are 
not  adapted  to  surfaces  moving  over  each  other  at  high  speed. 
Thus  fight  oils  are  chosen  for  machines  running  at  high 
speeds  and  where  the  pressures  between  the  lubricated  sur- 
faces is  not  great,  as  in  the  case  of  cream  separators.  Heavy 
oils  and  greases  are  used  where  the  pressure  is  great  and  the 
motion  slow,  as  on  axles.  Manufacturers  provide  special^ 
lubricants  for  nearly  every  purpose,  and  it  is  well  that  special 
oils  be  used  as  far  as  possible.  Gas  engine  cyfinder  oil  is  so 
made  as  to  stand  high  temperature;  and  although  other  oils 
may  be  as  good  a  lubricant  at  normal  temperature,  they 
would  be  worthless  at  the  temperatures  prevailing  in  the  gas 
engine  cylinder. 

Table  of  Coefficient  of  Friction.  The  following  table* 
indicates  in  a  general  way  the  influence  of  surfaces  of  different 
materials  and  different  lubricants  upon  friction. 

*From  "Bearings  and  Their  Lubrication,"  by  L.  P.  Alford. 


190 


AGRICULTURAL  ENGINEERING 

Coefficient  of  friction  of  various  surfaces. 


Surface  in  contact 


Condition  of  the 
surface 


Mutual  arrange- 
ment of  the  fibers 


Coefficient 
of  friction 


Oak  on  oak 
Oak  on  oak 
Beech  on  oak 
Cast-iron  on  oak 
Cast-iron  on  cast-iron 
Cast-iron  on  cast-iron 
Cast-iron  on  wrought  iron 
Cast-iron  on  bronze 
Balls  on  hardened  steel 
Rollers 


Dry 

Oily 

Coated  with  tallow 

Coated  with  tallow 

Dry 

Oily 

Coated  with  lard 

Coated  with  lard 


Perpendicular 
Parallel 


0.336 

0.108 

0.055 

0.078 

0.152 

0.144 

0.053 

0.070 

0.002* 

0.0099* 


Fig.    100.      A   plain 
bearing. 


♦Approximate  values;  coefficient  of  friction  varies  with  speed  and  load. 

Bearings.  The  bearings  are  the  parts  of  a  machine  which 
contain  the  rotating  parts.  When  the  bearings  are  a  sepa- 
rable part  of  the  machine  they  are  often  called  boxes. 
Bearing  should  be  designed,  first,  from 
material  which  will  give  a  low  coefficient 
of  friction;  second,  so  that  the  surfaces 
may  be  thoroughly  lubricated ;  third,  from 
materials  that  will  resist  wear  or  which 
can  be  easily  replaced;  and  fourth,  in  most  cases  they 
should  be  adjustable  for  wear. 

A  bearing  which  is  made  in  one  piece  and  is  separable 
from  the  rest  of  the  machine  is  styled  a  solid  box.  A  bearing 
supported  on  pivots  or  in  a  socket 
which  will  permit  its  axis  to  be  moved 
easily  is  called  a  self-aligning  bearing. 
The  rotating  part  which  comes  in 
contact  with  a  bearing  is  usually  desig- 
nated as  the  journal.  The  journal  is 
generally  made  of  a  harder  material 
than  the  bearing.  Thus  the  journal 
is  usually  made  of  steel  and  the  bearing  of  brass,  bronze, 


Fig.    101.      A   self-i 
ing  bearing. 


FARM  MACHINERY 


191 


or  babbitt.     When  made  of  different  materials  there  is  less 
tendency  for  the  surface  to  become  rough  and  abraded. 

Roller  and  Ball  Bearings.  Roller  and 
ball  bearings  substitute  rolling  friction  for 
sliding  friction.  Such  bearings  are  usually 
much  more  expensive  than  plain  bearings, 
but  in  many  places  the  extra  expense  is 
justified.  Roller  bearings  furnish  a  very 
satisfactory  means  of  holding  a  supply  of  the  lubricant  and 
prevent  binding  and  heating,  due  largely  to  misalignment. 


Fig.    102.      A   ball 
bearing. 


Fig.   103.     A  roller  bearing  for  wai^uns.      The  hub  of  the  wheel  fits  over 
the   rollers  shown. 


Ring  Oiling  Bearings.  A  ring  oiling  bearing  has  a 
reservoir  of  oil  underneath  the  shaft,  or  journal,  into  which  a 
ring  resting  on  the  upper  side  of  the  shaft  is  allowed  to  dip, 
and  as  the  shaft  rotates  the  oil  is  carried  up  onto  the  shaft, 

where  it  spreads  out  to 
each  side,  thoroughly  lu- 
bricating the  bearing. 
Such  a  bearing  is  very 
desirable  for  a  machine  in 
continuous  service. 
Inclosed  Wheel  Boxes.  It  is  customary  on  the  best 
machines  that  are  to  be  subjected  to  much  dust,  to  eiicki^ 
the  outer  end  of  the  wheel  boxes  and  provide  a  collar  at  the 
inside  end  of  such  a  construction  as  to  practically  exclude  all 
dust.    The  lubricant  is  usually  ''hard  oil"  or  heavy  grease, 


Fig.    104.      A   ring  oiling   bearing. 


192 


AGRICULTURAL  ENGINEERING 


Fig. 


105.      An    inclosed 
wheel  box. 


supplied  by  screwing  off  the  inclosed  end  of  the  wheel  box. 
The  grease  thus  works  toward  the  inside  end  of  the  box  and 
still  further  assists  in  excluding  the 
dirt  and  grit. 

Oil  and  Grease  Cups.  The  gen- 
eral character  of  a  machine  can  often 
be  determined  by  the  kind  of  oil  and 
grease  cups  used  on  the  machine. 
No  machine  should  be  purchased 
which  does  not  have  an  adequate  provision  for  lubricating 
all  bearings. 

Babbitting  Boxes.  Babbit  metal  is  a  mixture  of  several 
metals  having  a  rather  low  melting  point,  and  is  used  to  Hne 
boxes.  Genuine  babbitt  metal  is  mixed  in 
the  proportion  of  1  part  of  copper,  2  parts  of 
antimony,  and  from  6  to  24  parts  of  tin;  but 
the  name  is  applied  to  many  combinations  of 
metals  used  as  a  lining  for  boxes.  Besides 
furnishing  a  very  satisfactory  metal  for  a 
bearing,  babbitt  metal  can  be  quite  easily 
replaced. 

In  preparing  to  babbitt  a  box  it  is  neces- 
sary to  be  provided  with  a  melting  ladle  and 
a  fire,  preferably  a  forge  fire,  to  heat  it.  The 
worn  babbitt  which  is  to  be  replaced  is 
carefully  removed  with  a  cold  chisel  and  the 

box  freed  from  grease  and  moist- 
ure. The  shaft  is  carefully  blocked 
into  position,  leveled  and  centered, 
and  the  ends  of  the  box  closed  by 
cardboard  collars  fitting  around 
the  shaft  and  held  in  place  with 


Fig.  106.     A  sight 
feed  oil   cup. 


Fig 


107.      A     grease    cup 
feeding   hard   oil. 


putty  or  stiff  clay  mud. 


FARM  MACHINERY  193 

if  the  box  is  solid,  a  piece  of  writing  paper  is  wrapped 
around  the  shaft,  or  journal,  to  give  clearance  or  to  prevent 
the  box  from  being  too  light.  This  paper  is  held  in  place  by 
a  cord  which  burns  up  and  leaves  a  useful  oil  groove.  If  the 
box  be  split,  or  made  in  two  halves,  cardboard  Hners  should 
be  inserted  between  the  halves,  fitting  against  the  shaft  to 
divide  the  babbitt.  Notches  may  be  cut  in  these  liners  to 
let  the  molten  metal  flow  from  one  side  to  the  other.  When 
hardened,  the  metal  in  these  notches  may  be  broken  by  driv- 
ing a  cold  chisel  between  the  halves  of  the  box. 

It  is  usually  best  that  the  boxes  be  warmed  before  pour- 
ing the  metal,  and  the  metal  should  be  hot,  to  insure  that  it 
will  fill  every  part  of  the  box.  The  metal  is  usually  poured  in 
through  the  oil  hole.  When  the  metal  has  hardened  and  the 
box  removed,  the  oil  hole  should  be  drilled  out,  and,  if  the  box 
is  a  large  one,  oil  grooves  should  be  cut  to  lead  the  oil  away 
from  the  oil  hole,  to  insure  that  all  parts  of  the  bearing  will 
be  covered  with  oil.  Often  an  old  machine,  when  babbitted, 
will  run  like  a  new  one,  the  rattle  and  vibration  due  to  the  lost 
motion  in  the  bearings  being  overcome. 

Adjustment  of  the  Bearings.  The  proper  adjustment  of 
a  bearing  requires  much  skill.  If  the  bearing  be  too  tight,  it 
will  heat,  and,  if  too  loose,  it  will  knock  and  also  heat.  A  good 
rule  to  follow  is  to  screw  the  top  of  the  box  down  upon  paper, 
cardboard,  or  metal  strips  (called  liners)  between  the  halves 
of  the  box  until  the  box  is  rigid,  selecting  hners  of  such  thick- 
ness as  will  make  the  box  fit  the  shaft  as  tightly  as  possible, 
yet  offering  no  resistance  to  the  free  turning  of  the  shaft. 

QUESTIONS 

1.  Define  a  tool.     An  implement.     A  machine. 

2.  What  is  meant  by  the  efficiency  of  a  machine? 

3.  Name  the  elements  of  a  machine. 

7— 


194  AGRICULTURAL  ENGINEERING 

4.  What  are  the  three  essentials  of  a  practical  machine? 

5.  Why  is  the  selection  of  a  machine  important? 

6.  What  is  friction? 

7.  Define  the  coefficient  of  friction. 

8.  What  are  some  of  the  conditions  that  modify  the  coefficient  of 
friction? 

9.  What  would  be  the  draft  on  ice  of  a  sled  weighing  4000  pounds 
if  the  coefficient  of  friction  between  the  runners  and  the  ice  is  0.025? 

10.  Mention  several  instances  where  friction  is  especially  useful. 

11.  Why  is  friction  of  rest  greater  than  friction  of  motion? 

12.  What  is  the  cause  of  rolling  friction? 

13.  What  are  the  purposes  of  lubrication? 

14.  What  kind  of  lubricant  should  be  used  on  a  machine  like  a 
harvester? 

15.  Of  what  value  is  graphite  as  a  lubricant? 

16.  What  should  be  taken  into  account  in  the  design  of  a  bearing? 

17.  Why  should  the  material  used  for  the  bearing  be  different  from 
that  of  the  journal? 

18.  When  are  roller  and  ball  bearings  best? 

19.  Explain  t'ne  process  of  babbitting  a  box. 

20.  How  should  a  bearing  be  adjusted? 


CHAPTER  XXXI 
MATERIALS 

Importance  of  Quality.  The  durability  of  a  machine 
depends  largely  upon  the  quality  and  character  of  the  mate- 
rials used  in  the  construction  of  it.  It  is  obvious  that  a 
knowledge  of  the  properties  of  these  materials  will  be  use- 
ful to  those  who  have  to  do  with  the  selection  and  manage- 
ment of  machinery. 

Wood.  Twenty-five  to  forty  years  ago  the  framework 
of  farm  machinery  was  made  largely  of  wood.  At  that 
time  wood  stock  of  the  first  quaUty  and  of  the  most  desir- 
able varieties  could  be  obtained  cheaply.  The  increase  in 
the  cost  of  wood,  due  to  its  scarcity,  and  the  decreasing  cost 
of  manufacturing  iron  and  steel  has  led  to  a  more  extended 
use  of  metal.  The  wood  used  in  the  construction  of  farm 
machinery,  since  it  must  undergo  rather  severe  service, 
should  be  of  selected  quality.  Carefully  selected,  well-sea- 
soned heartwood  in  the  only  practical  kind  to  use. 

Wood  is  influenced  more  or  less  by  moisture,  and  for 
that  reason  should  be  carefully  protected  by  paint.  A 
combination  of  iron  and  wood  parts  is  likely  to  give  trouble 
by  becoming  loose,  due  to  the  shrinking  of  the  wood.  Parts 
subject  to  much  vibration,  like  the  pitman  of  a  mower,  can 
best  be  made  of  wood.  Excessive  vibration  and  shocks 
tend  to  cause  steel  to  crystallize. 

Some  of  the  more  common  varieties  of  woods  and  forms 
of  metal  used  in  the  construction  of  farm  machinery  will 
now  be  discussed. 

195 


196  AGRICULTURAL  ENGINEERING 

Hickory  is  a  very  dense,  heavy  wood  of  great  strength 
and  elasticity.  It  is  the  hardest  and  toughest  wood  used  in 
the  construction  of  farm  machinery  and  vehicles.  It  is 
preferred  to  all  others  for  axles,  buggy  spokes,  shafts,  etc. 

Oak  is  a  hard  wood  but  not  so  tough  as  hickory.  It  is 
used  to  some  extent  for  wagon  axles,  doubletrees,  and  gen- 
erally for  parts  where  stiffness  is  required.  The  best  kind 
of  oak  for  these  purposes  is  white  oak.  Red  oak  or  black 
oak  is  not  so  hard  and  stiff. 

Ash  is  hard,  tough,  and  elastic,  and  for  that  reason  is 
quite  generally  used  for  handles  of  hand  tools,  such  as  forks. 
It  is  a  white,  coarse-grained  wood 

Maple.  Hard,  or  ''rock  maple,"  is  a  hard,  fine-grained 
wood  which  is  quite  stiff,  and  is  being  used  to  some 
extent  as  a  substitute  for  hickory. 

Beech  is  a  hard,  strong  and  tough  wood  of  very  close 
grain  and  will  take  a  very  high  polish. 

Birch.  Black  birch  is  a  dark,  close-grained,  tough 
wood.  It  is  used  to  some  extent  for  wagon  hubs,  on  account 
of  its  resistance  to  checking. 

Poplar  is  a  wood  which  may  be  obtained  very  free  from 
knots.  It  is  light  yellowish  in  color,  has  a  close  grain,  and 
is  very  tough  compared  with  the  lighter  woods.  It  is  the 
standard  material  for  wagon  boxes  and  buggy  panels.  Cot- 
tonwood, a  very  close  relative  of  the  poplar,  is  used  to  some 
extent  as  a  substitute. 

Pine.  There  are  many  varieties  of  pine  to  be  had. 
Long  leaf  yellow  pine  has  a  decided  grain  and  is  quite  stiff. 
It  is  used  largely  in  the  construction  of  field  hay  tools  and 
for  similar  purposes.  White  pine  is  used  where  soft,  light 
wood  is  desired. 

Cast-iron.  The  cheapest  metal  used  in  the  construc- 
tion of  farm  machinery  is  cast-iron.     It  is  crystalline  in 


FARM  MACHINERY  197 

structure  and  it  can  not  be  forged  or  welded.  It  is 
shaped  by  machine  tools,  by  drilling,  turning,  or  planing. 
It  is  used  for  the  heavy  parts  of  machines,  for  gears  or 
where  irregular  shapes  are  desired,  which  may  be  obtained 
by  casting  molten  iron.  Cast-iron  may  be  usually  de- 
tected by  the  lines  and  roughness  given  to  it  by  the  sand 
mold  in  which  it  is  cast.  It  is  easily  detected  upon  breaking 
by  the  crystalline  structure. 

Chilled  Cast-iron.  Where  a  particularly  hard  surface 
is  desired,  a  special  kind  of  cast-iron  is  used,  obtained  by 
making  a  part  of  the  mold  of  heavy  iron,  which  chills  the 
molten  metal  as  soon  as  it  comes  in  contact  with  it  and 
makes  it  very  hard. 

Malleable  iron  is  cast-iron  which  has  been  annealed 
and  relieved  of  a  part  of  its  carbon  by  heating  in  furnaces 
for  several  days.  Malleable  iron  is  soft,  tough,  and  some- 
what ductile,  and  is  used  to  replace  cast-iron  where  these 
characteristics  are  required.  When  broken,  malleable  iron 
shows  a  soft  malleable  surface  and  a  crystalline  center. 

Cast  Steel.  Cast  steel  is,  in  brief,  cast-iron  less  a  part  of 
the  carbon.  It  is  less  brittle  than  cast-iron,  and  is  used  for 
gears  and  other  parts  subject  to  severe  stresses. 

Mild  and  Bessemer  Steel.  Most  of  the  material  now 
used  in  the  construction  of  farm  machinery  is  mild  or  Besse- 
mer steel,  which  is  made  by  a  special  process.  It  is  a  very 
tough  metal  whose  stiffness  can  be  regulated  by  the  manu- 
facturer by  varying  the  carbon  content.  It  can  be  easily 
forged,  but  does  not  weld  as  readily  in  an  open  fire  as 
wrought  iron. 

Wrought  Iron.  Wrought  iron  is  nearly  pure  iron.  It 
is  very  ductile  and  can  be  easily  forged  or  welded.  The 
purest  and  best  grade  of  wrought  iron  is  known  as  Norway 
or  Swedish  iron. 


198  AGRICULTURAL  ENGINEERING 

Soft-Center  Steel.  The  ability  of  carbon  steel  to  be 
hardened  depends  largely  upon  the  percentage  of  carbon 
it  contains.  When  hardened,  it  will  take  a  most  excellent 
polish,  as  is  desired  for  plows,  but  hardened  steel  is  brittle 
and  will  not  stand  shocks.  To  overcome  this  shortcoming, 
soft-center  steel  has  been  invented,  which  consists  of  a  layer 
of  soft  steel  between  two  layers  of  high-carbon  steel.  This 
soft,  low-carbon  steel  lends  toughness  to  the  whole  plate. 
Soft-center  steel  is  quite  generally  used  at  the  present  time 
in  the  manufacture  of  shovels  and  plows. 

Tool  Steel.  Tool  steel  contains  a  rather  high  percentage 
(0.6  to  1)  of  carbon,  is  capable  of  being  hardened  and  tem- 
pered, and  has  a  very  close,  dense  structure.  It  is  used  in 
the  manufacture  of  hand  tools,  such  as  hammers,  chisels, 
etc.  A  discussion  of  the  strength  of  materials  will  be  found 
in  Part  VII. 

QUESTIONS 

1.  Why  is  it  important  that  a  good  quality  of  material  be  used  in 
the  construction  of  farm  machinery? 

2.  Discuss  the  merits  of  wood  as  a  material  for  farm  machinery. 

3.  Describe  some  of  the  special  uses  for  wood. 

4.  Why  is  hickory  used  for  wagon  axles  and  buggy  spokes? 

5.  Compare  white  oak  with  hickory. 

6.  Suggest  some  good  uses  for  maple,  beech,  birch,  poplar,  and 
white  and  yellow  pine. 

7.  What  are  some  of  the  properties  of  cast- iron? 

8.  Describe  the  process  of  making  chilled  iron.     Malleable  iron. 

9.  For  what  purposes  is  cast  steel  used? 

10.  Why  are  Bessemer  and  mild  steel  used  so  largely  in  the  con- 
struction of  farm  machinery? 

11.  Describe  soft-center  steel  and  its  uses.     Also  tool  steel. 

12.  What  is  tool  steel,  and  mention  some  of  its  properties? 

Note:  Samples  of  the  various  materials  used  in  the  construction  of 
farm  machinery  should  be  collected,  and  machines  should  be  examined 
to  determine  the  materials  used. 


CHAPTER  XXXII 
THE  PLOW 

The  Plow.  The  plow  is  universally  recognized  as  the 
principal  and  most  fundamental  implement  used  on  the 
farm,  it  being  often  included  in  emblems  representing  the 
great  industry  of  agriculture.  The  plow  is  a  very  simple 
tool,  if  we  consider  the  walking  implement,  and  the  sulky 
or  gang  plow  is  not  exceedingly  compUcated.  Yet  in  the 
selection,  operation,  and  adjustment  of  the  plow  there  are 
many  important  features  to  be  considered. 

The  Selection  of  a  Plow.  As  with'  any  other  imple- 
ment, the  selection  of  a  plow  will  depend  in  a  large  measure 
upon  the  conditions  to  be  met.  A  farmer  owning  a  farm 
with  small  fields  would  not  want  a  steam  plow;  nor  would 
a  farmer  having  large  level  fields  want  small  walking  plows, 
when  a  single  driver  could  handle  a  gang  just  as  well.  The 
walking  plow  is  useful  in  small  lots  and  in  getting  close  to 
the  fence  in  finishing  up  the  lands  plowed  with  a  larger 
plow,  and  for  these  reasons  it  should  be  a  part  of  the  equip- 
ment of  every  farm. 

Size.  The  sizes  of  plow  which  should  be  selected  is 
determined  largely  by  the  condition  of  the  soil  and  the 
amount  of  power  or  the  number  of  horses  available.  The 
average  size  (width  of  furrow)  for  a  walking  plow  is  16 
inches,  and  the  horse  gang  usually  has  two  12-  or  14-inch 
plows,  or  bottoms,  as  they  are  called. 

Types  of  Plows.  There  are  three  distinct  types  of  plows 
upon  the  market,  as  classified  by  the  shape  of  the  mold- 
board:     First,  the  breaker,  with  a  long  moldboard  to  turn 

199 


200  AGRICULTURAL  ENGINEERING 

the  furrow  slice  of  tough  sod  gradually;  second,  the  general- 
purpose  plow,  to  be  used  for  general  plowing  in  stubble  and 
light  sod;  and,  third,  the  stubble  plow,  with  an  abrupt  mold- 
board  for  pulverizing  the  soil,  used  only  in  old  ground. 
Among  these  three  classes  there  are  numberless  shapes  of 
plows  difficult  to  classify. 


Fig.    108.      The    three    principal    types    of   plows,    showing    in    order    the 
stubble,  the  general  purpose,  and  the  prairie  breaker  plows. 

Construction.  The  moldboard  may  be  made  of  soft- 
center  steel  or  chilled  iron;  but  the  latter  is  used  but  very 
httle  in  the  Middle  West,  where  the  soil  is  of  such  a  character 
that  the  hard-tempered  surface  of  the  soft-centered  steel  is 
required  to  scour  properly.  Certain  locaHties  are  furnished 
with  plows  with  common  cast-steel  moldboards;  but  they 
can  not  be  used  where  many  rocks  are  encountered,  in 
which  case  a  soft  share,  at  least,  must  be  provided.  The 
wearing  properties  of  the  soft-centered  steel  share  is  secured 
through  its    hardness;    but  to  secure  hardness  a   certain 

amount    of     brittleness 
must  remain,  even  with  a 
soft  center  to  the  metal. 
Adjusting  the  Walk- 
ing  Plow.     The    walk- 
Fig.    109.     A  steel  beam   walking  plow   of    iug  ploW   mUSt    haVC   itS 
the  general-purpose  type.  p^-^^        ^^^^^         ^^^^ 

slightly  in  order  to  cause  the  plow  to  take  to  tlie  ground. 
This  gives  what  is  called  "suction"  to  the  plow,  and  is 
resisted  by  the  upward  pull  of  the  draft.  It  is  imperative 
that  the  suction  be  sufficient,  and  quite  as  important  that 


FARM  MACHINERY  201 

it  be  not  too  great.    With  the  proper  amount  of  suction  a 
plow  will  run  evenly,  as  far  as  depth  is  concerned.     To  test 

for  suction,  lay  a  straight-  ^  ^    ^— -~ 

edge  on  the  underline  of        ^^t::^^i^\^  ^.^^   ^_.^^^ '  3 

the    landside    when    the  I  — — — ■» 

plow      is      turned     bottom  Fig      no.      illustrating     method       of 

.  -  Ti?    XT.  •  using     a     straight-edge     to      determine 

side     up.       11    there    is     an        whether   a   plow   has    the   proper    "suc- 

opening  of  about  J^  of  an  ' 

inch  between  the  straight-edge  and  the  landside  at  the 
joint  between  it  and  the  share,  the  suction  is  about  correct. 
To  lift  and  bend  the  furrow  shce,  a  certain  amount  of 
pressure  must  come  upon  the  outer  comer,  or  wing,  of  the 
share.  To  resist  or  carry  this  pressure,  a  certain  amount 
of  surface,  or  '* bearing,"  is  provided  to  rest  upon  the  bottom  ^ 
of  the  furrow  as  the  plow  is  drawn  along.  If  this  bearing 
is  too  great,  the  plow  will  be  continually  tending  to  turn  out 
from  the  land,  and  if  insufficient  will  turn  in  the  opposite 
direction.  The  amount  of  bearing,  or  the  width  of  surface 
at  the  corner  of  the  share,  varies  with  the  condition  of  the 
^^^^^^^  ^    soilj    but    \}/i   inches    is 

^    ^^^^^^^^BB^^^'^     about  correct  for  a  16-inch 
^^^^^^^^^^^^^^^E|=:^     plow.     The  bearing    sur- 
Fig   111.    A  share  with  the  proper     face  is  triaugular  iu  shapc, 

form     at    the    wing.       The     contact    or  ■%     .  n  u       x      o 

"bearing"    at    C    should    be    about    IV*        and     IS     USUally    aOOUt      6 
inches   wide    for   a    16-inch   plow.  .^^j^^^    j^^^^ 

Steel-beam  walking  plows  have  an  advantage  in  clearance, 
and  for  this  reason  are  more  satisfactory  in  plowing  under 
trash  and  weeds.  On  the  other  hand,  wooden-beam  walking 
plows  are  slightly  lighter. 

Sulky  or  Gang  Plows.  Riding  plows  with  moldboards 
may  be  divided  into  two  classes,  frame  and  frameless,  and 
are  constructed  with  and  without  tongues.  The  frameless 
and  tongueless  plows  are  of  the  cheaper  construction;  but, 


202 


AGRICULTURAL  ENGINEERING 


Fig.     112.       A    frameless    and    tongueless 
sulky  plow   g^lided  by  the   hitch. 


although  they  have  the  advantage  of  Hghtness,  they  do  not 
have  certain  advantages  secured  in  the  frame  and  tongued 
plows.     The  frame  type  has  the  plow  connected  to  the  frame 

by  means  of  bails  or  some 
similar  device.  This  per- 
mits the  plow  to  be  lifted 
high  out  of  the  ground, 
designating  it  a  ''high- 
lift"  plow.  This  fea- 
ture is  a  decided  ad- 
vantage for  cleaning. 
The  frameless  plow  has 
the  wheels  attached  di- 
rectly to  the  plow  beam  by  means  of  brackets.  This 
simplifies  the  construction;  but  frameless  plows  are  not  high- 
lift.  This  type  cannot  usually  be  set  to  ''float,"  so  that  in 
case  a  rock  is  struck  in  plowing  the  plow  may  be  hfted  out 
of  the  ground  without  interfering  with  the  carriage  or  the 
driver. 

The  tongue  on  the  high-class  sulky  plow  is  used  to  steer 
the  plow  by  be- 
ing connected 
to  the  furrow 
wheels  by  means 
of  suitable  Hnk- 
age,  thus  en- 
abling a  square 
corner  to  be 
turned  in  either 
direction.  The 
tongue  gives  more  complete  control  over  the  plow,  and,  in 
the  opinion  of  the  author,  is  an  essential  part.  Another 
desirable  feature  to  have  on  any  plow  is  a  footlift,  which 


Fig.    113.     A  high-lift  frame  gang   plow. 


FARM  MACHINERY 


203 


enables  the  driver  to  control  the  plow  by  the  feet,  leaving 
the  hands  free  to  drive.  The  frame  plow  with  a  high  lift, 
footlift,  and  tongue  has  many  complications  as  far  as  con- 
struction and  operation  are  concerned,  but  is  well  worth  the 
difference  in  price  over  a  more  simple  plow.  Gang  plows 
have  the  same  constructional  features  as  sulky  plows,  except 
that  two  bottoms  instead  of  one  are  provided. 

The  Adjustment  of  Sulky  and  Gang  Plows.  In  operat- 
ing the  sulky  or  gang  plow,  every  effort  should  be  made 
to  have  the  plow  travel  straight  to  the  front  and  to 
have  all  of  the  downward  pressure,  due  to  lifting  the  furrow 
slice,  and  the  side  pressure,  due  to  turning  the  furrow  slice, 
borne  by  the  carriage  of  the  plow. 
To  do  this  the  point  must  al- 
ways be  turned  down  sufficiently 
to  cause  the  plow  to  take  the 
ground  at  all  times.  No  pres- 
sure should  be  allowed  on  the  sole 
of  the  plow,  as  this  will  cause  c  - 
unnecessary  friction.  All  pres- 
sure as  far  as  possible  should 
come  on  the  wheels,  which,  with 
their  lubricated  bearings,  will  re- 
duce friction  to  a  minimum. 

To  give  the  sulky  plow  suc- 

,•  ,1  r  11  Fig.    114.   A   plan    of   a   high- 

tion,  the  rear  furrow  wheel  may   nft  frame  suiky  plow  showing 

VI  J  x'l    J.1-        i_       1        r    xi-         t^^   manner  in   which   the  rear 

be   lowered   until    tne    neel    Ot    tne     furrow   wheel    is  set  to   relieve 


landside  lacks  about 


inch  of 


the   friction  on  the  landside. 


touching  when  the  plow  is  placed  upon  a  level  sur- 
face. To  carry  the  landside  pressure,  the  rear  furrow  wheel 
should  be  set  outside  of  the  line  of  the  landside,  usually 
about  1}4:  inches.     It  must  also  be  turned  slightly  away 


204  AGRICULTURAL  ENGINEERING 

from  the  land,  and  the  front  furrow  wheel  regulated  to  keep 
the  large  land  wheel  traveling  directly  to  the  front. 

Draft  of  Plows.  The  draft  or  pull  required  to  move  a 
plow  at  work  varies  widely  with  the  soil  conditions  and  the 
adjustment  of  the  plow.  The  draft  will  vary  from  4  to  10 
poimds  to  each  square  inch  of  cross  section  of  the  furrow  slice, 
the  method  of  comparision  commonly  used.  In  stubble 
ground  the  draft  should  not  exceed  4J/^  pounds  per  square 
inch  of  the  furrow.  Thus  a  16-inch  plow  running  six  inches 
deep  will  have  a  furrow  with  a  cross-section  of  96  square 
inches.  If  the  draft  be  43/^  pounds  per  square  inch  the  total 
draft  will  be  432  pounds,  an  easy  load  for  three  1300-  to 
1400-pound  horses. 

A  sulky  plow  with  a  driver  of  medium  weight  will  run  with 
as  Hght  draft,  when  in  proper  adjustment,  as  a  walking  plow. 
This  is  due  to  the  reduction  of  sole  and  landside  friction.  A 
plow  out  of  adjustment  will  often  pull  half  again  as  heavy  as 
it  should. 

In  making  a  selection  of  a  sulky  plow,  care  should  be  taken 
to  see  that  all  parts  subject  to  wear  can  be  easily  renewed. 
The  greater  part  of  a  sulky  plow  is  not  subject  to  wear  and 
will  last  indefinitely  if  not  broken.  The  modern  plow 
must  have  wheel  boxes  which  will  not  only  exclude  all  dirt 
but  also  provide  a  magazine  for  a  liberal  supply  of  grease. 
Many  sulky  plows  are  now  constructed  with  too  light  a  frame. 
Choice  should  be  made  of  the  heavy,  rigid  plow,  even  if  the 
cost  is  slightly  higher  and  the  draft  slightly  greater. 

The  Disk  Plow.  There  are  two  conditions  under  which 
the  disk  plow  will  do  good  work.  The  hard,  dry  soils  of  some 
of  the  Western  states  are  more  easily  subdued  by  means  of 
the  disk  plow  than  any  other.  These  soils  at  certain  times 
of  the  year  are  turned  up  in  lumps  by  the  common  plow,  but 
the  disk  plow  cuts  its  way  through  the  lumps  and  breaks 


FARM  MACHINERY  205 

them  up.  Yet  the  disk  plow  cannot  be  used  in  extremely 
hard  ground,  such  as  might  be  found  in  a  road,  as  it  could 
not  be  kept  in  the  ground.  The  other  soil  condition  to  which 
the  disk  plow  is  well  adapted  is  where  the  soil  is  so  sticky 
that  the  moldboard  plow  fails  to  scour  well,  as  in  heavy 
clay  or  gumbo  soils.  The  black,  waxy  soil  found  in  Texas 
and  other  parts  of  the  South  is  such  a  soil.  The  disk  plow 
with  its  scraper  to  clean  the  disk  will  turn  a  furrow  regardless 
of  the  scouring  properties  of  the  soil.     Where  the  moldboard 


^^^«^^&,  T*"^ 

's 

,/smi^i 

» 

1 

S 

■ 

S 

i 

m 

' 

Fig.   115.     A   modern   disk   gang  plow  at  work. 

plow  will  do  good  work,  it  is  to  be  preferred  to  the  disk  plow. 
As  generally  constructed,  the  latter  is  a  very  clumsy  imple- 
ment and  very  heavy,  the  weight  being  necessary  to  keep 
the  plow  in  the  ground.  Claims  for  its  hghtness  of  draft 
cannot  be  substantiated  by  tests  when  compared  with  mold- 
board  plows  under  favorable  moisture  conditions.  Often 
the  disk  plow  is  given  credit  for  doing  more  work  than  it 
actually  performs,  in  that  the  bottom  of  the  furrow  is  not 
flat  and  measurements  are  often  made  of  the  deepest  point. 
The  diameter  of  the  disk  proper  varies  from  20  to  30 
inches  in  different  plows.  A  24-inch  disk  will  do  the  most 
satisfactory  work  under  usual  conditions.     It  pulverizes  the 


206  AGRICULTURAL  ENGINEERING 

soil  to  the  best  advantage, — more  so  than  a  smaller  disk, — 
and  is  not  of  as  heavy  draft  as  a  larger  disk.  A  disk  blade 
26  or  28  inches  in  diameter  can  be  used  for  a  longer  period, 
because  much  more  metal  is  provided  for  wear. 

The  disk  plow  does  not  have  a  tongue  and  does  not  make 
as  good'corners  as  the  modern  high-class  sulky  plows.  If  the 
disk  is  of  proper  shape  and  size,  the  plow  pulverizes  and  mixes 
the  soil  thoroughly,  which  features  are  essential  in  good  plow- 
ing. This  plow  will  cover  standing  weeds  to  good  advantage, 
but  loose  trash  is  troublesome.  It  cannot  be  used  at  all  in 
tough  sod. 

It  is  a  mistake  to  try  to  cut  too  wide  a  furrow  with  a  disk 
plow.  A  furrow  with  a  width  greater  than  8  inches  results 
in  more  or  less  ' 'cutting"  or  ''covering." 

The  vital  parts  of  a  disk  plow  are  the  disk  and  its  bearing. 
The  former  should  be  constructed  of  the  best  of  material, 
for  which  the  faith  of  the  manufacturer  must  be  taken,  and 
the  bearing  should  have  plenty  of  material  to  resist  wear 
and  reliable  means  of  excluding  dirt  and  providing  lubrica- 
tion. 

Deep -Tilling  Machine.  This  is  a  new  machine  which 
has  come  upon  the  market  within  the  last  two  years,  and,  as 

far  as  providing 
a  means  of  plow- 
ing the  soil  to  a 
greater  depth 
than  hitherto  is 
concerned,  it  is 
a  success.  The 
machine  is  a  disk 
gang  plow  with 
the  second  or 
,,.     .   .      ..„.  ^.  rear  disk  set  to 

Fig.     116.     A    deep-tilling    machine. 


FARM  MACHINERY  207 

plow  a  furrow  in  the  bottom  of  the  furrow  made  by  the  first. 
In  this  way  it  is  entirely  possible  to  plow  to  a  depth  of  16 
inches  or  even  more.  The  disks  are  large  and  they  do 
the  best  work  when  cutting  a  furrow  12  inches  wide. 

The  draft  of  this  tool  is  surprising.  When  tested  in  a 
loam  soil  with  a  clay  subsoil,  the  draft,  when  plowing  a  12-inch 
furrow  and  16  inches  deep,  was  between  800  and  900  pounds. 
A  16-inch  sulky  plow  when  forced  to  its  capacity  for  depth 
(eight  to  nine  inches)  gave  a  draft  between  900  and  1000 
pounds,  or  about  100  pounds  more.  By  comparing  the 
sizes  of  these  various  furrows  it  is  to  be  noticed  that  the  draft 
of  the  tilling  machine  was  very  satisfactory.  Again,  it  would 
be  quite  impossible  to  plow  so  deep  with  anything  except  a 
special  plow  of  this  character. 

Hillside  and  Reversible  Plows.  The  hillside  plow  is 
a  reversible  plow  adapted  to  a  field  with  so  much  slope  that 
it  would  be  quite  impossible  to  throw  a  furrow  uphill.  The 
plow  is  changed  from  a  right-hand  to  a  left-hand  plow  by 
revolving  the  plow  so  that  the  furrow  is  turned  either  to  the 
right  or  to  the  left. 

The  reversible  plow  was  formerly  confined  to  the  hillside 
type,  yet  there  is  a  tendency  at  the  present  time  to  make  a 
more  extended  use  of 
this  type  of  plow.  Its 
use  in  the  irrigated 
sections,  where  dead 
furrows  are  to  be  avoid- 
ed if  possible,  is  of 
great  importance.  The 
advantage  of  dispens- 
ing with  dead  furrows 

n    ^J  J    i-i  ^'&-    ll'^-      -^  reversible   disk   plow.      This 

m  any  nela,  and  thus  plow  is  made  to  turn  a  right  or  left  fur- 
1  .  .1  /.  row    by  swinging  the    hitch    from   one    end 

leavmg     the     surface     to  the  other. 


208 


AGRICULTURAL  ENGINEERING 


level,  is  worthy  of  consideration.  In  Europe,  the  reversible 
plow  has  been  in  more  extended  use  than  in  this  country. 

The  moldboard  type  of  reversible  plow  consists  of  two 
plow  bottoms,  a  right-  and  a  left-hand,  which  are  used  alter- 
nately. These  plows  do  not  have  many  of  the  conveniences 
of  the  high-hft  sulky  and  do  not  possess  the  usual  provisions 
for  relieving  the  landside  friction  by  placing  the  load  on  the 
carriage.  It  is,  however,  an  entirely  practical  tool.  The 
reversible  disk  plow  is  so  arranged  that  by  swinging  the  team 
and  hitch  about  to  the  opposite  direction,  the  inclination  of 
the  disk  is  changed,  but  the  carriage  is  left  unchanged  and 
is  simply  drawn  across  the  field  in  the  reverse  direction.  It 
would  seem  that  this  implement  has  reached  a  higher  state 
of  development  than  its  moldboard  mate. 

Tractor  Gang  Plows.  The  use  of  the  tractor  for  plow- 
ing   requires  for  the  best  service  special  plows  adapted  to 


Fig.    118.      An  engine   gang  plow. 

the  special  requirements  of  tractor  power.  Tractor  gang 
plows  are  made  with  moldboard  and  disk  plows  and  range 
in  size  from  two  to  fourteen  furrows. 

In  general  there  are  two  types,  one  the  flexible  beam 
shown  in  Figure  118,  in  which  each  plow  or  pair  of  plows 
may  be  handled  independently,  and  the  rigid  beam,  Fig.  118a, 


FARM  MACHINERY  209 

in  which  the  plows  are  fastened  rigidly  together  and  raised 
or  lowered  as  a  unit.  The  flexible  beam  type  consists  in  a 
heavy  triangular  frame,  carried  on  wheels,  all  or  a  part 
of  which  are  arranged  to  castor  or  are  guided  by  the  hitch 


Fig.  118a.     Rigid  beam  gang  plow. 

through  suitable  linkage.  The  plows  are  attached  to  the 
rear  of  the  frame  and  are  generally  controlled  by  levers  ex- 
tending forward  over  a  platform  placed  on  the  frame.  These 
levers  may  be  attached  either  to  a  single  plow  or  to  a  pair. 
Quite  a  little  variance  is  found  in  the  location  of  the  gauge 
wheel  which  regulates  the  depth  of  the  furrow.  The  gang 
wheel  should  be  so  located  that  the  furrow  depth  will  be 
influenced  as  little  as  possible  by  an  uneven  surface. 

The  ''rigid  beam"  type  of  tractor  plow  is  used  exclusively 
for  the  disk  gang  and  is  generally  confined  to  small  sizes, 
two  to  four  bottoms  when  made  for  moldboard  plows.  It 
is  desirable  with  small  tractors  to  have  an  outfit  which  may 
be  operated  by  one  man.  For  this  reason  the  levers  are 
generally  turned  toward  the  front  where  they  may  be  con- 
veniently reached.  Disk  tractor  plows  resemble  horse  disk 
gangs  except  that  they  are  made  much  heavier.  Plows  are 
now  made  with  power  lifts  enabling  the  tractor  operator  by 
pulling  a  rope  to  engage  a  clutch  which  sets  in  motion 
mechanism  which  raises  the  plows  by  power  from  the  wheels 
of  the  gang  plow.  The  power  lift  is  adapted  to  both  the 
flexible  and  rigid  beam  types  of  tractor  gangs. 


210  AGRICULTURAL  ENGINEERING 

Adjusting  the  tractor  gang  consists  primarily  in  setting 
the  plows  for  the  proper  amount  of  suction  and  proper  spac- 
ing. The  gang  should  be  attached  to  the  tractor  so  as  to 
cause  each  plow  to  be  drawn  straight  through  the  soil. 

Any  type  of  plow  bottom  may  be  used  in  the  tractor 
gang  plow  from  the  sod  to  the  stubble  bottom.  Shares  are 
now  made  ''quick  detachable,"  enabling  the  shares  to  be 
removed  for  sharpening  by  loosening  one  nut  or  lever. 

QUESTIONS 

1.  Why  is  the  plow  considered  the  principal  implement  on  the  farm? 

2.  What  are  some  of  the  most  important  factors  to  be  considered 
in  the  selection  of  a  plow? 

3.  How  is  the  size  of  a  plow  designated,  and  what  are  some  of  the 
common  sizes? 

4.  What  are  the  distinct  plow  types  on  the  market? 

5.  Of  what  materials  are  the  plow  moldboard  and  share  made? 

6.  Describe  the  adjustment  of  a  walking  plow. 

7.  What  is  meant  by  the  suction  of  a  plow?  The  bearing  at  the 
wing? 

8.  What  is  the  difference  between  a  frame  and  a  frameless  plow? 

9.  Describe  what  is  meant  by  high  lift. 

10.  How  should  sulky  plows  be  adjusted? 

11.  How  is  the  draft  of  a  plow  kept  low  by  adjustment? 

12.  What  constructional  features  should  be  given  consideration 
in  making  a  selection  of  a  sulky  plow? 

13.  Under  what  conditions  will  the  disk  plow  work  better  than  the 
moldboard  plow? 

14.  What  are  the  common  sizes  of  disks  and  disk  plows,  and  what 
size  of  furrow  will  they  turn? 

15.  Describe  the  construction  of  the  deep-tilling  machine. 

16.  Describe  the  construction  of  hillside  and  reversible  plows,  and 
explain  their  use. 

17.  Describe  the  construction  of  the  moldboard  engine  gang. 

18.  How  are  the  plows  raised  and  lowered? 

19.  What  adjustments  are  of  primary  importance? 

20.  Describe  the  construction  of  the  disk  engine- gangs. 


CHAPTER  XXXIII 


HARROWS,  PULVERIZERS,  AND  ROLLERS 

HARROWS 

Utility  of  the  Smoothing  Harrow.  Perhaps  there  is 
no  other  tillage  tool  on  the  farm  which  is  more  effective  than 
the  common  spike-toothed  smoothing  harrow,  when  used 
under  the  proper  conditions  and  at  the  proper  time.  It 
smoothes  and  pulverizes  the  surface,  producing  a  fine  tilth, 
which  not  only  prevents 
a  loss  of  moisture  by 
evaporation  but  also 
destroys  a.  multitude  of 
weeds  at  the  time  when 
they  are  the  least  able 
to  withstand  cultivation. 

Selecting  a  Smooth- 
ing Harrow.  The  stand- 
ard harrow  of  the  day  is 
the  steel  lever  harrow 
for  four  horses,  covering  a  width  of  15  feet  or  more.  A 
harrow  with  a  spread  of  from  10  to  15  feet  is  a  size  suitable 
for  a  three-horse  team. 

A  lever  harrow,  which  enables  the  teeth  to  be  inchned 
forward  for  penetration  and  backward  for  smoothing,  costs 
slightly  more  than  a  plain  harrow  or  even  an  adjustable  tooth 
harrow;  but  the  harrow  at  most  is  not  an  expensive  implement 
and  the  lever  harrow  is  well  worth  the  difference  in  cost.  One 
of  the  principal  advantages  of  the  lever  harrow  hes  in  the 
convenience  in  cleaning.    The  adjustable  tooth  has  a  clamp 

211 


Fig.  119.  A  modern  U-bar  smoothing 
harrow  with  protected  tooth  bars.  A  har- 
row   cart   Is  attached. 


212  AGRICULTURAL  ENGINEERING 

which  permits  the  teeth  to  be  held  in  a  perpendicular  position 
when  drawn  in  one  direction  or  in  an  inclined  position  when 
drawn  in  the  opposite  direction.  The  harrow  is  reversed  by 
changing  the  evener  from  one  side  of  the  harrow  to  the  other. 

All  harrows  may  at  first  seem  alike,  yet  there  is  much 
difference  in  their  construction.  There  is  no  doubt  but  that 
some  harrows  are  made  as  cheaply  as  possible  to  sell  for  a 
low  price.  Of  course  there  are  conditions  where  the  soil  is 
easily  cultivated  and  a  light  harrow  is  desirable;  yet,  as  a  rule, 
the  amount  of  cultivation  performed  is  in  proportion  to  the 
weight  and  number  of  teeth  in  the  harrow.  Stony  ground 
will  require  a  heavier  construction  than  would  otherwise  be 
necessary. 

Construction  of  the  Smoothing  Harrow.  The  tooth 
bars  are  commonly  made  of  the  so-called  U  bar  or  pipe.  The 
former  seems  to  be  the  stronger  for  the  weight  of  metal 
used.  The  teeth  may  be  had  in  two  sizes,  one-half  or  five- 
.^.^  ^L^  „  eighths  inch  square,  the 

^?  3  i*         If  ^    larger,  of  course,    being 

I  ^J^  ^^      adapted  to  heavy  serv- 

*         y^J[^^  I  ir''niiwj?w«i»B«a-    \Q^.      All    the   teeth 

should  have  large  heads 
to  prevent  loss  should  a 
fastener     become     loos- 

Fig.    120.      A   pipe-bar    smoothing    har- 
row.       Common     methods      of      fastening    enCQ.  iue    UUmbcr    01 

teeth  are   illustrated.  j.      x i  •        /•  •       i 

teeth  varies  from  six  to 
eight  per  foot  of  width.  It  stands  to  reason  that  the  greater 
number  of  teeth  will  do  more  in  pulverizing  the  soil. 

For  use  in  orchards,  the  harrow  with  protected  tooth 
bars  has  a  decided  advantage,  since  the  bars  will  not  do 
much  damage  by  catching  upon  the  trees.  As  a  smoothing 
harrow  is  too  wide  to  pass  through  the  average  farm  gate,  it 
should  be  convenient  for  dissembling  and  assembling. 


FARM  MACHINERY  213 

The  Spring-Tooth  Harrow.  The  spring-tooth  harrow, 
with  flat  spring  teeth  bent  almost  to  a  complete  circle,  is  a 
tool  that  is  not  in  general  use  in  America,  but  implements 
of  a  similar  character  are  used  to  a  large  extent  in  Europe. 
It  should  be  classed  as 
a  cultivator  rather  than 
a  harrow.  It  is  adapted 
to  hard,  compact  soils 
which  require  a  tool  of 
good  penetration.  The 
teeth  have  such  long 
blades    with    so    much 

.,      .     .,  ,  .  Fig.    121.      A   spring-tooth   harrow. 

sprmg  that  the  machme 

is  not  damaged  in  passing  over  stones  or  low  stumps. 
The  draft  of  a  spring-tooth  harrow  will  depend  upon  the 
adjustment  given  to  the  teeth,  but  under  average  condi- 
tions it  greatly  exceeds  that  of  a  smoothing  harrow. 

The  Harrow  Cart.  Probably  there  is  not  another  imple- 
ment attachment  that  can  be  bought  for  the  same  money  that 
will  dispense  with  so  much  hard  labor  as  the  harrow  cart.  To 
be  a  satisfactory  device  it  must  be  rigidly  built  with  angle  or 
U-bar  arms  extending  to  the  harrow  evener,  with  provision 
for  the  cart  wheels  to  castor  in  turning.  The  wheels  should 
be  high,  32  inches  being  a  good  height,  and  provided  with 
tires  about  three  inches  wide.  They  should  also  have  dust- 
proof  removable  boxes  with  easy  means  of  lubrication. 
Lastly,  it  should  not  be  overlooked  that  the  cart  should 
be  provided  with  a  comfortable  seat  and  springs  to  support  it. 

Utility  of  the  Disk  Harrow.  The  disk  harrow  is  an 
implement  well  adapted  to  deep  surface  cultivation.  For 
this  reason  it  is  used  for  a  variety  of  purposes.  To  prepare 
plowing  for  seed  in  the  spring  or  stubble  for  plowing  in  the 
fall,  it  is  equally  useful.     For  covering  broadcasted  seed  in 


214 


AGRICULTURAL  ENGINEERING 


corn  stalk  ground  it  has  many  advantages  over  the  shovel 
cultivator.  In  the  first  place  it  is  more  rapid,  and,  more- 
over, a  double  disking  will  effectively  reduce  the  stalks. 
In  subduing  a  sod,  there  is  no  other  tool  that  will  do  the 
work  of  the  disk  harrow.  In  dry-farming  localities  it  has 
been  found  to  be  one  of  the  best  tools  to  produce  a  soil 
mulch  for  preserving  the  soil  moisture.     Orchardists  use  it 


Fig.    122.      A   disk   harrow   at   work. 


for  cultivating  orchards.  It  is  used  in  renewing  alfalfa  fields, 
as  it  cuts  or  splits  the  crowns  of  the  plants,  thus  thickening 
the  stand. 

The  disk  harrow  can  be  made  to  do  the  work  of  the  stalk 
cutter  and  at  the  same  time  cultivate  the  ground  in  the  early 
spring,  preparing  it  for  plowing.  As  a  rule  two  diskings  will 
not  cut  comstocks  as  well  as  going  over  the  field  once  with  a 
stalk  cutter,  but  nevertheless  a  good  job  is  done.     This 


FARM  MACHINERY 


215 


system  of  disposing  of  the  stalks  and  cultivating  the  soil  be- 
fore plowing  cannot  be  too  highly  commended.  Many 
weeds  are  destroyed  and  a  better  seed  bed  is  obtained  upon 
plowing. 

Construction  of  the  Disk  Harrow.  The  standard  disk 
harrow  has  full  round  disk  blades,  sixteen  inches  in  diam- 
eter and  about  sixteen  in  number,  spaced  six  inches  apart. 
This  is  the  four-horse  machine.  Smaller  disk  blades  do 
not  give  sufficient  clearance,  and  larger  sizes  do  not  do 
as  effective  work.  The  sixteen-inch  disk  rotates  faster  than 
a  larger  disk  and  so  pulverizes  the  ground  more,  and  it  also 
has  less  bearing  surface  under  the  working  edge,  insuring 
greater  penetration. 

Disk  harrows  have  one  lever  by  means  of  which  both 
disk  gangs  are  adjusted  at  the  same  time,  or  two  levers,  one 
for  each  gang,  permitting  individual  adjustment.  The  two 
levers  are  almost  essential  when  ''lapping  half,"  or  allowing 


Fig.    123.      A   full-blade,    two-lever   disk   harrow    with    tongue    truck. 


216 


AGRICULTURAL  ENGINEERING 


Fig.   124.     A   cutaway  disk  harrow. 


the  disk  to  extend  half  way  over  the  work  of  the  previous 
round.  The  merit  of  this  method  hes  in  the  fact  that  the 
ground  is  left  nearly  level,  while  a  single  disking  will  leave  the 

ground  sMghtly  ridged. 
When  this  method  is  fol- 
lowed, the  disk  gang  work- 
ing on  the  once  disked 
ground  finds  less  resist- 
ance than  the  gang  work- 
ing in  the  undisked  ground. 
By  setting  the  gang  in 
the  loose  soil  at  a  sharper 
angle,  the  machine  is  balanced  and  the  soil  pulverized  more 
than  otherwise.  The  two-lever  machine  also  has  a  decided 
advantage  in  hillside  work.  The  tendency  of  the  machine 
to  crowd  downhill  may  be  overcome  to  a  large  extent  by 
a  separate  adjustment  of  the  gangs. 

•T3rpes  of  Disk  Harrow.  Disk  harrows  are  built  in 
three  general  types,  as  far  as  the  construction  of  the  disk  is 
concerned.  First,  there  is  the  full-hladed  disk  with  solid  per- 
fectly round  edges;  second,  the  cutaway  or  cut-out  disk, 
which  is  Uke  the  full-bladed  disk  except  that  notches  are 
cut  out  of  the  edge,  leav- 
ing short  points  to  enter 
the  ground;  third,  the 
spading  disk  harrow 
which  consists  of  a  series 
of  sharp  blades  curved  at 
the  end  and  made  up  into 
a  sort  of  sprocket  wheel. 

For  average  conditions  the  full-bladed  disk  is  the  best. 
It  has  a  greater  pulverizing  action,  is  stronger,  and  is  more 
effective  in  cutting  up  trash  and  stalks.    Another  very  im- 


Fig.     125.      A    spading    disk    harrow. 


FARM  MACHINERY  217 

portant  advantage  of  this  type  is  the  convenience  of  sharpen- 
ing. These  disks  may  be  sharpened  to  a  good  edge  by  means 
of  any  of  the  disk  sharpeners  which  will  do 
good  work.  About  the  only  way  that  the 
notches  of  the  cutaway  disk  may  be  sharpened 
is  by  removing  all  of  the  disks  and  grinding 
them  to  edge  on  an  emery  wheel.  The  blades 
of  a  spading  harrow  are  sharpened  by  heating 
each  individual  knife  and  drawing  out  the 
edge  with  a  hammer  while  hot. 

The  cutaway  harrow  is  very  deceiving  in 
the  amount  of  work  it  does.  The  blades 
sprinkle  the  soil  over  the  surface  in  such  a  way 
that  the  unstirred  soil  underneath  is  hidden. 
This  harrow  has  a  decided  advantage  in  cul- 
tivating and  renovating  old  pastures.  Where 
the  fuU-bladed  disk  would  cut  the  stubble  up 
and  destroy  it,  the  cutaway  will  loosen  the 
soil  in  such  a  way  as  to  stimulate  growth. 

*^  '^  Fig.    126.     A 

In  the  amount  of  work  done,  the  spading    piow-cut  disk 
harrow  is  much  uke  the  cutaway.    The  prm- .  harrows.  Note 
cipal  advantage  of  the  spading  harrow  lies  in     center, 
its  ability  to  work  in  wet  ground,  when   the  full-bladed 
disk  would  be  sure  to  clog. 

The  "plow  cut"  disk  has  a  bulged  or  raised  center,  it  being 
claimed  that  the  soil  will  be  more  nearly  turned  over  when 
coming  in  contact  with  this  center.  The  name  might  imply 
some  sort  of  plow  action,  but  the  work  of  this  type,  as  far  as 
the  writer  has  observed,  does  not  differ  much  from  the 
ordinary    disk    harrow. 

Alfalfa  Harrow.  The  alfalfa  harrow  is  a  special  tool 
with  sharp  spikes  arranged  as  disks  in  the  frame  of  a  common 


218 


AGRICULTURAL  ENGINEERING 


WWBi. 


Fig.    127.      An   alfalfa    harrow. 


disk  harrow.     This  new  implement  is  certain  to  become 

very  popular  for  cultivating  alfalfa  fields. 

Scrapers.     A   disk   harrow   should    be    provided   with 

scrapers  or  cleaners  which 
will  keep  the  disks  clean 
imder  all  conditions.  The 
scraper  with  a  rather  nar- 
row chisel  blade  which 
can  be  moved  from  the 
center  to  the  outside  of 
the  disk  is  very  satisfac- 
tory   and    is   used   upon 

a  large  number  of  modern  disk  harrows. 

Bearings.    The  part  that  receives  the  most  wear,  except 

the  cutting  edges  of  the  disks  themselves,  is  the  bearings. 

Both  chilled  iron  and  wooden  boxes  a^re  used.    The  wood 

seems  to  be  the  more  satisfactory,  not  only  on  account  of 

durability,  but  also  on  account  of  the  ease  of  replacement. 

Maple  boiled  in  oil  is  generally  used  for  the  bearings,  yet  any 

hard  wood  might  answer. 

Ball-and-socket  joints  between  the  disks  are  not  generally 

satisfactory.     If   the   bearings 

do    not    care    for    the    entire 

thrust  of   the   gangs,    bumper 

plates  seem  to  be  the  most  sat- 
isfactory   devices.     These  are 

large  oval  washers  on  the  ends 

of   the  gang  bolts  which   run  mg.  128 

through  the  center  of  the  disks. 

Tongue  Truck.    The  modern  disk  harrow  has  a  tongue 

truck.    This  device  reheves  the  horses  of  the  most  tiresome 

part  of  the  work  when  the  harrow  is  used  on  loose  and  rough 

ground.    With  a  tongue  truck,  side  lashing  is  prevented. 


A  good  form  of  bearing 
for  disk   harrows. 


FARM  MACHINERY 


219 


Trucks  which  have  tongues  assist  in  keeping  the  team  straight 
and  also  prevent  the  horses  from  backing  into  the  harrow. 
The  trucks  should  have  reasonably  large  wheels  and  be 
strongly  made.  The  axles  should  provide  for  lubrication, 
be  dust  proof,  and  have  interchangeable  boxes. 

Transport  Truck.  Another  convenient  device  to  use  in 
connection  with  the  disk  harrow  is  the  transport  truck, 
especially  if  the  harrow  is  to  pass  over  any  hard  road.  This 
device  consists  of  wheels  mounted  on  levers  in  such  a  manner 
that  the  gangs  may  be  lifted  from  the  ground,  thus  securing 
the  desired  protection. 


Fig.    12! 


A    harrow   attachment    for  a   plow   at   work. 


Harrow  Attachments  for  Plows.  Those  who  have  had 
the  experience  know  that  a  harrow  will  do  the  most  effective 
work  when  following  the  plow.  Attention  has  been  called 
by  agricultural  writers  to  the  desirabiUty  of  harrowing  each 
day's  plowing  before  the  close  of  the  day.  The  harrow  attach- 
ment has  been  designed  to  harrow  and  smooth  each  furrow  as 
soon  as  turned.  There  are  three  types  in  use,  one  with  blades 
which  resemble  those  of  a  pulverizer,  another  is  a  rotary 
affair  with  blades  like  a  spading  disk  harrow,  and  still  another 


220 


AGRICULTURAL  ENGINEERING 


kind  has  small  round  disks.  Each  of  these  works  much  like 
the  machines  after  which  they  are  patterned.  They  are 
made  in  sizes  suitable  for  either  sulky  or  gang  plows,  and 
are  quite  easy  to  attach.  They  interfere  sHghtly  with  the 
adjustments  of  the  plow,  but  this  matter  can  easily  be  over- 
come. The  draft  of  those  for  sulky  plows  will  vary  from 
50  to  100  pounds,  depending  upon  the  pressure  applied. 
This  means  that  the  attachment  provides  about  one-half 
to  two-thirds  of  a  load  for  one  average  horse. 

LAND  ROLLERS 

T3rpes  of  Rollers.    The  plain,  smooth  land  roller  has 
been  replaced  to  a  large  extent  by  tubular,  corrugated ,  or 

disk  types.  The  change 
has  been  due  to  some  of 
the  objectionable  features 
of  the  work  of  the  smooth 
roller.  It  is  desirable,  in 
most  instances,  not  to 
leave  the  surface  of  the 
ground  perfectly  smooth 
and  compact.  It  is  true 
that  for  crops  to  be  har- 
vested with  the  mower 
this  feature  is  desirable,  but  a  smooth  surface  usually  means 
an  unnecessary  loss  of  moisture.  On  a  smooth  surface  there 
is  no  soil  mulch,  and  the 
wind  has  a  greater  dry- 
ing effect. 

Of  the  various  types 
of  rollers  recently  placed 
upon  the  market,  the 
disk  roller,  composed  of  Fig.  isi.   a  disk  roiier. 


Fig.    130.     A  plain   land  roller. 


FARM  MACHINERY  221 

cast-iron  disks  with  wedge-shaped  treads,  spaced  about 
four  inches  apart  and  weighing  about  100  pounds  per 
foot  of  width,  is  perhaps  the  most  satisfactory.  This  imple- 
ment not  only  thorDughly  packs  the  soil  beneath  the  surface 
but  also  collects  and  crushes  the  clods  and  leaves  the 
surface  slightly  rough  and  covered  with  a  mulch. 

Selecting  a  Roller.  In  selecting  a  roller,  the  bearings, 
strength  of  construction,  and  weight  are  the  principal  fea- 
tures which  should  be  given  consideration  after  the  type 
of  machine  has  been  decided  upon.  Hard-wood  boxes 
make  the  most  satisfactory  bearings.  If  the  ground  is 
uneven,  a  flexible  frame  should  be  chosen,  as  there  will  not 
only  be  less  chance  of  breakage  in  the  roller  but  better  work 
will  be  performed. 

PULVERIZERS 

The  name  pulverizer  is  given  to  a  variety  of  tools.  It 
usually  designates  certain  curved-tooth  harrows  of  the  Acme 
type  and  also  rollers  of  the 
cast-iron  type.  In  some 
locaUties  the  disk  harrow 
is  referred  to  as  a  pulver- 
izer. It  seems,  however, 
that  the  implement  best 
described    by   this  name      fi&.  132.    a  pulverizer  with  rake 

•^  attached. 

IS  the   one   with    curved 

spring  knives,  either  with  or  without  a  leveHng  rake.  This 
tool  has  not  become  very  popular  with  farmers  generally, 
but  it  seems  to  be  gaining  favor  of  late.  The  tendency 
has  been  to  try  to  perform  the  same  work  by  means  of 
the  common  smoothing  harrow. 

The  pulverizer  does  efficient  work  in  producing  a  fine 
tilth.    It  is  especially  useful  in  destroying  small  weeds  just 


2;n  AQRIGVLTVRAL    ENGINEERING 

coming  through  the  ground.  The  knives  tear  the  weeds 
out  and  the  rake  behind  drags  them  free  of  the  soil  and  leaves 
them  on  the  surface  to  be  destroyed  by  the  sun.  The  drag- 
ging action  of  the  pulverizer  is  also  very  good  in  leveling  an 
uneven  surface.  The  draft  of  the  pulverizer  is  less  than 
that  of  the  disk  harrow,  an  eight-foot  pulverizer  drawing 
about  as  hard  as  a  six-foot  disk  harrow. 

QUESTIONS 

1.  What  is  the  work  of  the  smoothing  harrow? 

2.  Describe  the  difference  in  construction  between  the  adjustable 
tooth  harrow  and  the  lever  harrow. 

3.  Describe  some  of  the  important  constructional  features  of  the 
smoothing  harrow. 

4.  Describe  the  construction  of  the  spring-tooth  harrow,  and  under 
what  conditions  it  will  render  the  best  service? 

5.  Why  is  the  harrow  cart  useful  and  what  should  be  its  construc- 
tion? 

6.  For  what  work  is  the  disk  harrow  adapted? 

7.  Describe  some  of  the  general  features  of  the  construction  of  the 
disk  harrow. 

8.  What  are  the  three  general  types  of  disk  harrows? 

9.  Describe  the  plow-cut  disk  blade.     The  alfalfa  harrow. 

10.  What  is  the  purpose  of  the  scrapers  on  a  disk  harrow? 

11.  Why  are  the  bearings  important  on  a  disk  harrow? 

12.  Of  what  use  is  a  tongue  truck? 

13.  Describe  the  construction  of  harrow  attachments  for  plows. 

14.  Describe  three  types  of  land  rollers. 

15.  Explain  some  of  the  important  points  to  be  considered  in  select- 
ing a   land  roller. 

16.  To  what  purpose  is  the  pulverizer  adapted? 

17.  Describe  the  construction  of  the  curved-tooth  pulverizer. 


CHAPTER  XXXIV 
SEEDERS  AND  DRILLS 

Utility  of  Seeders  and  Drills.  The  seeder  should  be  used 
only  where  the  drill  is  impractical,  as  it  is  not  a  machine 
adapted  to  the  most  improved  methods  of  farming.  The 
drill  enables  all  the  seed  to  be  covered  at  a  uniform  depth 
and  to  be  very  uniformly  distributed.  The  broadcast  seeder 
may  distribute  the  seed  uniformly,  but  the  harrow  or  other 
implement  which  follows  it  will  not  cover  the  seed  at  a  uni- 
form depth,  meaning  that  a  part  of  the  seed  is  placed  too 
deep  and  a  part  too  shallow.  The  sa\dng  of  seed  alone  in 
sowing  a  large  field  is  often  sufficient  to  practically  pay  for 
a  drill.  There  are  certain  seeds,  however,  that  must  be 
covered  very  shallow,  and  the  modem  drill  is  not  well  adapted 
for  the  purpose.  At  one  time  grass  seed  was  broadcasted 
on  meadows  to  thicken  the  stand,  but  the  drill  has  been 
found  to  do  this  work  more  satisfactorily. 

SEEDERS 

Hand  seeders  are  used  on  rough  ground  where  horse 
machines  can  not  be  used.  A  very  satisfactory  type  is  the 
crank  machine  with  a  whirling  distributor.  It  is  not  possible 
to  secure  a  very  even  seeding  in 
this  way,  but  that  is  often  quite 
unavoidable.  This  type  of  machine 
should  have  an  agitator  for  feeding 
the  grain  to  the  distributor.  No 
attempt  should  be  made  to  use  the 
machine  on  a  windy  day.  pi^,  issT^hand  seedir. 

2J 


224 


FARM  MACHINERY 


Fig.    134.      A   wheelbarrow   seeder. 


The  wheelbarrow  seeder  is  preferred  by  some  in  sowing 
grass  seed.  At  one  time  the  grain  seeder  lacked  refinement 
for  grass  seeding.  The  wheelbarrow  seeder  usually  has  an 
agitator  feed,  which  is  not  accurate,  to  say  the  least.    This 

agitator  consists  of  a 
rod  beneath  the  seed 
box  which  stirs  the 
seed  in  such  a  manner 
as  to  cause  it  to  flow 
out  of  the  opening  on 
the  under  side  of  the  box  in  a  fairly  uniform  stream. 

Endgate  seeders  have  one  desirable  feature,  and  that 
is  their  great  capacity.  The  seeding,  however,  is  never  very 
uniform.  As  far  as  known,  all  machines  of  this  class  have 
whirhng  distributors,  which  are  either  single  or  duplex.  The 
latter  are  claimed  to  have  more  capacity  and  to  be  more 
accurate  than  the  single  distributor  machines.  To  improve 
their  accuracy  some  makes  of 
endgate  seeders  are  provided 
with  a  force  feed  to  the  dis- 
tributor. There  is  no  doubt 
that  this  is  a  good  feature  and 
should  be  on  all  such  seed- 
ers. Friction  and  gear  drives 
are  used  to  drive  the  distribu- 
tor. Spiral  gears  seem  to  be 
the  most  satisfactory,  but 
care  should  be  used  in  starting  the  machine  so  as  not  to 
cause  breakage. 

Seedbox  broadcast  seeders  are  used  to  a  considerable 
extent.  These  are  commonly  eleven  feet  wide  and  mounted 
either  upon  wheels  at  each  end  of  the  box  or  upon  a  low  wheel 
truck  underneath.     The  truck  type  does  not  lash  the  tongue 


Fig.   135.     An  endgate  seeder. 


FARM  MACHINERY  225 

SO  much  in  passing  over  uneven  ground,  and  for  most  condi- 
tions is  to  be  preferred.  The  box  may  be  placed  low,  and 
only  distributing  funnels  used  to  spread  the  seed,  or  the  box 
may  be  placed  higher  and  the  distributing  funnels  placed  at 
the  lower  ends  of  seed  tubes.  The  latter  has  not  been  very 
satisfactory,  as  the  tubes  are  either  easily  broken  or  lost. 
The  seed,  of  course, 
should  be  released  quite 
near  the  ground  so  as 
not    be    interfered  with 

by  the  wind.       This  type      *^ig.    uq^ a   broadcast   seedeTwlth    a' 

of    seeder     may     have  narrow-track  truck, 

either  the  agitator  feed  previously  described,  or  a  force 
feed.  The  first  type  consists  of  a  stirring  wheel  over  an 
opening  through  which  the  grain  is  allowed  to  flow.  The 
force  feed  is  by  far  the  more  accurate,  and  will  be  described 
under  drills. 

DRILLS 

Furrow-openers.  Grain  drills  are  now  equipped  with 
four  types  of  furrow-openers,  the  single-disk,  the  double- 
disk,  the  shoe,  and  the  hoe.  An  idea  of  the  construction  of 
each  may  be  obtained  from  the  accompanying  illustrations. 

The  single-disk  is  the  best  for  most  conditions.  It  has 
better  penetration  and  will  cut  through  trash  better  than 
any  other  type.  Furthermore,  it  has  only  one  bearing  per 
disk  to  wear  out,  whereas  the  double-disk  has  two.  The 
single-disk  must  have  one  half  of  the  disk  turned  in  the  oppo- 
site direction  from  the  other  half  in  order  to  keep  the  machine 
balanced.  This  is  a  disadvantage,  as  it  causes  the  ground 
to  be  left  slightly  uneven,  which  necessitates  that  the  drill  be 
followed  with  a  harrow  on  rolling  ground  to  prevent  soil 
washing.    The  single-disk  furrow-opener  may  be  provided 


226 


AGRICULTURAL   ENGINEERING 


with  a  closed  boot,  which  provides  a  complete  passageway 
for  the  seed  to  the  bottom  of  the  furrow  independent  of  the 


Fig.   137.     A  standard   sinsle-disk  drill  at  work.     This  machine  has   IS 
furrow-openers  spaced    7   inches   apart. 

disk;  or  with  the  open  boot,  which  depends  upon  the  disk 
blade  to  supply  one  side  of  the  seed  tube.  The  closed  form 
is  less  likely  to  become  clogged,  but  the  open  style  provides 
a  slightly  wider  seed  row. 

The  double-disk  does  not  have  quite  the  penetration 
that  the  single-disk  has,  but  when  the  disks  are  quite  sharp 
this  type  of  opener  is  good  for  cutting  through  trash.  The 
claim  is  advanced  that  the  principal  merit  of  the  double-disk 


Fig.    138.      Single-disk,    double-disk,    shoe,    and    hoe   furrow-openers    for 
grain   drills.      The   single-disk   has   a   closed  boot,   or   shoe. 


FARM  MACHINERY 


227 


lies  in  the  wide  furrow  that  it  makes,  with  a  shght  ridge  in 
the  center.  Definite  experiments,  as  far  as  known,  have  not 
been  conducted  to  prove  any  advantage  of  this  kind  of 
furrow. 

The  shoe  drill  has  been  almost  entirely  displaced  by  the 
disk  drill.  It  is  a  lighter  draft  typ^,  and  where  penetration 
is  not  desirable  it  may  be  the  type  to  select.  The  hoe  drill 
has  good  penetration  but  can  not  be  used  where  there  is  any 
trash  to  contend  with. 

Force  Feeds.  Two  types  of  force  feeds  are  used  on  drills. 
The  most  common  is  the  external  feed  with  a  fluted  seed 


Fig.  1 


The  external  force  feed  is  shown  at  the  left,  and  the  internal 
device   at    the   right. 


shell.  The  amount  of  seeding  is  varied  by  slipping  the  shell 
in  a  guard  so  as  to  expose  in  the  seed  cups  more  or  less  of  the 
fluted  parts  as  required.  The  second  type  is  the  internal 
feed  with  a  ribbed  ring  to  which  the  seed  passes  on  the  inside. 
This  type  does  not  vary  the  size  of  the  cells  on  the  ring,  but 
the  feed  regulation  is  obtained  by  varying  the  rotative  speed 
of  the  ring  by  a  change  of  gears.  Usually  two  sizes  of  seed 
cells  are  provided  in  the  ring,  one  for  small  seeds  and  one  for 
large  seeds.    The  internal  feed  is  the  best  type  for  drilling 


228  AGRICULTURAL  ENGINEERING 

large  seeds  like  peas  or  beans.  The  cells  of  the  ring,  being  of 
a  certain  uniform  size,  will  not  crush  the  seed  like  the  external 
feed.  For  small  grain  the  external  feed,  however,  is  the  most 
accurate  and  is  the  most  convenient  of  adjustment.  This 
type  will  drill  at  a  quite  uniform  rate  regardless  of  the  amount 
of  seed  in  the  seedbox. 

Press  Drills.  The  press  drill  with  press  wheels  to  follow 
each  furrow-opener  is  the  most  satisfactory  type  for  fall  seed- 
ing. The  press  wheel  packs  the  soil  firmly  around  the  seed, 
causing  the  moisture  to  come  up  from  below  by  capillary 
action  and  thereby  producing  early  germination.  For  spring 
seeding,  when  there  is  an  abundance  of  moisture  in  the  soil, 

the  press  wheel  is  a  dis- 
advantage. In  regions 
where  both  spring  and  fall 
seeding  are  practiced,  the 
press  wheel  attachment, 
which  can  be  used  when 
desired,  is  a  satisfactory 
arrangement. 

Selecting  a  Drill.    In 
selecting  a  drill  with  disk 

Fig.    140.      A  press  drill.  /.  xi.       i- 

furrow-openers,  the  bear- 
ings and  the  means  of  oihng  the  bearings  should  be  care- 
fully inspected.  The  bearings  are  the  first  parts  to  wear 
out.  A  good  strong  frame  is  important,  as  well  as  a 
trussed  and  braced  seedbox.  The  best  designs  do  not 
depend  upon  the  seedbox  to  support  the  drill,  except  in  a 
minor  way. 

Seed  Tubes.  Rubber,  wire,  and  steel  ribbon  seed  tubes 
are  used  on  drills.  The  rubber  tubes  are  quite  satisfactory, 
but  are  not  durable,  especially  if  not  well  protected  from  the 
weather.     Steel   wire  tubes  are   satisfactory  except   when 


FARM  MACHINERY 


229 


stretched,  when  there  is  no  way  of  shortening  the  tubes  and 
filling  the  cracks.  The  steel  ribbon  is  no  doubt  the  best  of 
all,  as  it  is  affected  only  by  rust. 

Adjustment.  The  furrow-openers 
should  have  a  convenient  means  of  ad- 
justing the  spacing.  A  double  drag-bar 
is  without  doubt  preferable  to  the  single 
one.  The  common  spacings  of  furrow- 
openers  are  six,  seven,  and  eight  inches. 
For  the  average  conditions,  seven  inches  is 
a  very  satisfactory  spacing.  Seven-inch 
drills  are  usually  made  with  12  or  18  fur- 
row-openers. The  latter  is  a  good  size 
suitable  for  four  horses,  and  will  cover 
three  corn  rows  of  3  J^  feet  each. 

Horse  Lift.  The  horse  lift  for  large 
drills  is  a  great  convenience.  To  be  com- 
plete, the  drill  should  have  a  grass  seed      mg.  ui.  a  section 

,  ,       i  i  •,,•  1^1         ot    the    seed    box    of 

attachment,  permittmg  grass  seed  to  be  a  driii  showing  loca- 
drilled  with  other  crops.  The  footboard  box  and^l  ^s?ee1  hI^ 
is  preferred  by  some  to  a  seat.  This  is  **°"  *"^®* 
a  matter  largely  of  personal  preference,  but  the  footboard 
permits  the  driver  to  shift  from  one  side  to  the  other 
to  manage  the  driving  better.  A  double  capacity  or  auxiliary 
seedbox  may  now  be  had  with  many  drills.  This  obviates 
the  necessity  of  filling  the  seedbox  so  often. 


QUESTIONS 

1.  What  advantage  has  the  grain  drill  over  the  seeder? 

2.  Describe  the  use  and  construction  of  hand  and  wheelbarrow 
seeders. 

3.  How  is  the  grain  distributed  with  the  endgate  seeder? 

4.  Describe  the  various  methods  of  constructing  the  seed-box 
broadcast  seeder. 


230  AGRICULTURAL  ENGINEERING 

5.  What  two  types  of  feed  are  used  in  broadcast  seeders? 

6.  Describe  the  construction  and  the  relative  merits  of  the  various 
types  of  furrow-openers  used  on  grain  drills. 

7.  Describe  two  types  of  force  feed  for  drills. 

8.  For  what  conditions  is  the  press  drill  adapted? 

9.  What  are  the  important  features  to  be  considered  in  the  selection 
of  a  drill? 

10.  Of  what  material  are  the  seed  tubes  made? 

11.  What  is  the  common  spacing  of  furrow-openers? 

12.  What  is  a  horse  hft  for  a  drill? 


CHAPTER  XXXV 
CORN  PLANTERS 

Essentials  of  a  Com  Planter.  The  modern  corn  planter 
is  a  highly-developed  implement  and  well  able  to  meet 
the  exacting  demands  made  upon  it.  A  good  planter  will 
fill   the   following   conditions: 

First,  a  corn  planter  is  expected  to  place  in  every  hill  a 
certain  number  of  kernels  of  com. 

Second,  the  corn  must  be  placed  at  a  uniform  depth, 
regardless  of  the  condition  of  the  soil  or  trash  that  may  inter- 
fere. 

Third,  the  check-rower  must  place  the  corn  accurately 
in  rows  for  cross  cultivation. 

Fourth,  the  planter  must  be  convenient  to  operate. 

Fifth,  the  planter  must  be  capable  of  adjustment  to  the 
planting  of  cane,  beans,  and  several  of  the  other  crops  grown 
on  the  general  farm. 

No  doubt  accuracy  is  the  first  requisite  of  the  modern 
planter.  In  selecting  a  planter,  therefore,  the  dropping 
mechanism  should  be  given  first  consideration. 

The  Dropping  Mechanism.  There  are  two  distinct 
types  of  dropping  mechanism  upon  the  market,  the  full-hill 
drop  and  the  accumulative  drop.  In  the  full-hill  drop  a  seed 
cell  is  provided  large  enough  to  contain  the  desired  number 
of  kernels  for  one  hill  (as  three,  for  instance).  These  three 
kernels  are  all  counted  out  at  one  time,  and  if  they  should 
be  shghtly  undersized  it  would  be  easy  for  a  fourth  to  sHp 
in  as  the  seed  plate  containing  the  seed  cell  passed  under  the 
seedbox. 

231 


232 


AGRICULTURAL  ENGINEERING 


The  accumulative  drop,  on  the  other  hand,  provides  seed 
cells  in  the  seed  plate  large  enough  to  contain  only  one  kernel 
at  a  time.  The  hill  is  formed  by  receiving  in  a  receptacle 
the  desired  number  of  kernels  from  as  many  cells.  The 
accumulative  drop  would  appear  at  once  to  be  the  more 


Fig.   142. 


A  modern  corn  planter  with  long  shoe  furrow-openers,  vari- 
able drop,  and  open  wheels. 


accurate  of  the  two  types,  and  it  may  be  demonstrated  that 
it  is,  when  seed  corn  graded  to  size  is  used.  As  the  cell  in 
the  accumulative  drop  is  made  to  contain  one  kernel  only, 
it  is  evident  that  great  care  must  be  used  in  making  the  cell, 
and  even  then  there  will  be  difficulty  in  caring  for  odd-shaped 
kernels  whose  volume  may  not  be  much  different  from  the 
average.  These  ill-shaped  kernels  are  those  from  the  butts 
and  tips  of  the  ears,  and  when  an  accumulative  drop  planter 
is  used  they  must  be  discarded. 


FARM  MACHINERY  233 

The  edge-selection  drop,  now  quite  generally  used  by- 
manufacturers,  is  an  accumulative  drop  with  the  cells  in  the 
seed  plate  constructed  deep  and  narrow  to  receive  the  kernel 
on  the  edge  instead  of  on  the  flat,  as  ar- 
ranged for  in  the  so-called  flat  plate. 
The  edge-selection  plate  provides  very 
deep  seed  cells  from  which  there  is  Uttle  ^^^  ^^^  ^^^  ^^^^_ 
possibilitv  of  the  corn's  being  dislodged     selection  and  round- 

Y  ^  in  ^°'^    ^^®^    plates. 

by  the  cut-ort  which  covers  the  cell  as 
it  passes  over  the  receiving  receptacle.    There  is  danger, 
however,  of  the  kernel's  becoming  damaged  by  being  caught 
in  the  cell  on  end  in  such  a  way  that  the  cut-off  cuts  the  kernel 
in  two. 

Graded  Seed.  The  planter  will  do  more  accurate  work 
if  provided  with  carefully  graded  com,  and  this  fact  should 
never  be  overlooked.  After  removing  the  butts  and  tips, 
the  corn  should  be  run  through  a  good  corn  grader,  and 
then  there  should  be  a  careful  selection  of  plates  to  suit  the 
corn  to  be  planted.  Different  varieties  of  corn  and  com 
from  different  localities  differ  much  in  size  and  shape,  and 
accuracy  of  drop  can  only  be  secured  when  the  plates  are 
carefully  selected  for  the  corn  at  hand.  Sometimes  the 
proper  plates  are  not  furnished  with  the  planter,  and  new 
plates  better  suited  for  the  corn  at  hand  must  be  secured 
from  the  manufacturer.  There  are  usually  three  sizes  of 
plates  furnished  with  each  planter,  and  these  will  accommo- 
date nearly  all  of  the  variations. 

The  variable  drop  mechanism  is  of  recent  origin.  By  its 
use  the  seed  plate  is  made  to  count  out  from  two  to  four  ker- 
nels by  simply  shifting  a  lever  to  the  designated  notch.  This 
device  can  be  used  to  best  advantage  in  hilly  fields  where 
the  fertihty  of  the  soil  varies  much,  enabling  fewer  kernels 
to  be  planted  in  the  hills  where  the  soil  is  thin. 


234 


AGRICULTURAL  ENGINEERING 


It  also  dispenses  with  many  of  the  plates  which  must  be 
furnished  with  a  planter  that  does  not  have  the  device. 
Furrow-openers.    The   long   shoe   furrow-opener   is    in 

more  general  use  than  any 
other  type.  It  has  good 
penetration  and  is  easy  to 
guide.  Where  there  is 
trash  in  the  way,  the  stub 
runner,  which  hooks  un- 
der the  trash,  should  be 
used.  The  single-disk 
furrow-opener  has  good 
penetration  and  should  be 
used  in  soil  that  often 
becomes  very  compact 
the  com  can  be 
It  is  quite  im- 
to  make  perfectly  straight  rows  with  the  disk 
The  bearings  of  the  disks  are  subject  to  wear,  and 
the  single  disk  throws  the 
earth  to  one  side  in  open- 
ing the  furrow,  making 
the  covering  difficult.  The 
double-disk  furrow-opener 
offers  additional  compH- 
cations  without  material 
advantages.  It  is  some- 
times maintained  that  the 
disk  planter  is  of  fighter  Fig.  145. 
draft.  Even  if  this  be 
true,  the  planter  under  any  circumstances  is  not  a  heavy 
draft  implement. 

Wheels.    The  accepted  type  of  wheel  for  corn  planters 


Fig.  144. 

possible 
planter. 


A  corn  planter  with  stub  shoe   beforC 
furrow-openers. 

planted. 


A   corn  planter  with   disk  fur- 
row-openers. 


FARM  MACHINERY 


235 


is  the  open  wheel.  The  wheel  is  depended  upon  to  cover 
the  corn  and  pack  the  soil  over  it.  To  do  this,  the  open 
wheel  not  only  offers  an  improvement  over  the  flat  or  concave 
wheels,  but  is  much  easier  to  keep  clean.  The  open  wheel 
has  two  tires  about  one  and  one-half  inches  wide  and  set 
about  two  inches  apart.  These  two  tires  are  so  set  as  to 
draw  the  soil  together  over  the  furrow  made  by  the  furrow- 
opener. 

The  double-wheel  type  has  two  wheels  to  follow  each 
furrow-opener.  These  wheels 
are  capable  of  being  adjusted 
so  as  to  draw  the  earth  over 
the  furrow  as  desired.  Corn 
planter  wheels  are  made  in 
various  heights  to  accommodate 
the  machine  to  the  varying 
conditions  as  they  may  arise. 
Thus,  in  certain  sections,  the 
com  is  planted  in  furrows  made  by  the  lister,  and,  to  span  the 
high  ridges  between  the  furrows,  very  high  wheels  are 
necessary. 

Conveniences.  There  are  many  devices  to  be  found  on 
the  modern  planters  which  are  designed  to  save  time.  The  tip- 
over  seedbox  is  one.  Thus,  if  it  is  desired  to  change  the  seed 
in  a  seedbox  for  any  reason,  it  is  not  necessary  to  pick  out 
the  seed  corn  kernel  by  kernel.  A  reel  on  which  to  wind 
the  check  wire  as  the  last  row  is  planted  is  another  convenient 
device.  There  are  two  general  forms  of  reels  in  use;  one  is 
hung  under  the  seat,  and  the  other  is  placed  on  a  bracket 
over  the  planter  wheel  at  either  side.  The  first  location  is 
the  most  convenient  when  preparing  to  reel  the  wire;  but  the 
side  location  permits  the  wire  to  be  reeled  as  the  last  row  is 
planted,  the  reeUng  being  in  plain  sight  of  the  driver  and 


Fig.     146.      The    open    and    double 
types    of  corn  planter  wheels. 


236  AGRICULTURAL  ENGINEERING 

there  is  no  necessity  of  crossing  the  wire  with  the  team. 
Some  friction  device  must  be  used  to  drive  the  reel. 

The  double  marker,  or  a  separate  marker  for  each  side 
and  which  may  be  raised  to  a  vertical  position  when  not  in 
use,  is  undoubtedly  the  most  convenient  marker.  There 
is  less  time  consumed  in  putting  it  in  use  and  there  is  no 
crossing  of  the  Hnes  with  the  draw  rope.  Where  the  soil  is 
hard  the  disk  marker  should  be  used  in  preference  to  the 
drag  head  marker. 

Adjustment.  In  addition  to  a  selection  of  the  proper 
seed  plate,  or  calibration  of  the  planter,  as  it  is  sometimes 
called,  the  machine  should  be  kept  in  proper  adjustment  and 
good  working  condition  when  in  the  field.  One  of  the  more 
usual  neglects  of  this  kind  is  the  failure  to  keep  the  planter 
''front,"  the  part  of  frame  which  supports  the  runners, 
level.  If  the  front  be  tipped  back  or  forward,  the  corn  will 
be  deposited  in  hills  back  or  ahead  of  its  proper  location  and 
will  not  form  perfect  rows  crosswise. 

QUESTIONS 

1.  What  are  the  essentials  of  a  good  corn  planter? 

2.  What  is  the  difference  between  the  "full  hill"  and  the  accumula- 
tive drop? 

3.  Why  is  it  important  to  have  graded  seed? 

4.  What  is  the  variable  drop? 

5.  Describe  the  various  styles  of  furrow-openers  used  on  corn 
planters,  and  give  their  merits. 

6.  What  types  of  wheels  are  used? 

7.  What  are  some  of  the  conveniences  used  on  modern  planters? 

8.  How  should  planters  be  adjusted  for  accurate  check-rowing? 


CHAPTER  XXXVI 
CULTIVATORS 

Development.  The  development  of  the  corn  cultivator 
exemplifies  and  tjT)ifies  the  development  of  agricultural 
methods 'during  the  past  century.  Originally  corn,  or  maize, 
to  be  more  accurate,  was  planted  and  cultivated  almost 
entirely  with  the  hoe.  Later,  the  single-  or  double-shovel 
cultivator  was  introduced  to  assist  the  hoe.  Still  later  the 
straddle  or  single-row  cultivator  was  developed.  At  the 
present  time  the  double-row  cultivator  is  typical  of  modern 
methods.  The  single-  and  double-shovel  cultivators  have 
been  discarded  from  field  operations,  and  only  the  single- 
and  double-row  cultivators  are  left. 

Selection  of  a  Cultivator.  Whether  or  not  the  double-row 
cultivator  can  be  made  to  do  the  same  quaUty  of  work  with 
greater  economy  than  the  single-row  is  a  question  that  many 
farmers  are  trying  to  decide.  The  solution  of  this  problem 
will  depend  largely  upon  local  conditions.  It  is  unquestion- 
ably true,  however,  that  the  successful  use  of  the  two-row 
cultivator  depends  upon  careful  farming  at  all  times  in  pre- 
paring the  ground  and  in  planting  and  tending  the  crops. 
The  two-row  cultivator  is  not  an  implement  well  designed 
to  select  and  destroy  individual  weeds,  nor  is  it  capable  of 
being  adjusted  to  cultivate  each  hill  of  corn,  regardless  of 
whether  or  not  that  hill  may  be  in  a  straight  row.  The  two- 
row  cultivator  is  used  successfully  where  good  farming  sup- 
plies fields  comparatively  free  from  weeds,  well-prepared 
seed  beds,  and  straight  corn  rows.  If  this  high-class  farming 
is  practiced,  the  two-row  cultivator  will  be  found  a  necessary 

237 


238  AGRICULTURAL  ENGINEERING 

part  of  the  equipment  of  the  modern  corn  grower.  The  use 
of  the  two-row  cultivator  is  a  question  upon  which  opinions 
of  some  of  the  best  farmers  differ.  This  indicates  that,  in 
addition  to  the  necessary  field  conditions  mentioned,  the 
personal  factor  is  one  that  makes  for  success  or  failure. 

Walking  Cultivators.  The  walking  cultivator  is  made 
both  with  and  without  a  tongue.     The  advantages  of  the 

tongueless  kind  are  that 
they  are  light  and  re- 
quire less  turning  room 
than  the  other.  The 
difference  in  cost  is  small. 
On  the  other  hand,  the 

Fig.     147.       A    tongueless    walking    culti-        tOUgUelcSS      CUltivator 
vator   with   wooden   gangs. 

works  very  well  only 
with  a  well  broken  'and  evenly-gaited  team. 

Cultivator  Construction.  As  one-  and  two-row  cultivators 
have  many  features  in  common,  they  will  be  discussed  to- 
gether. Perhaps  the  most  important  feature  to  be  decided 
upon  in  the  selection  of  a  cultivator  is  the  shovel  equipment. 
Shovel  cultivators  are  provided  with  from  four  to  eight 
shovels  for  each  two  gangs.  By  gang  is  meant  the 
beam,  the  shanks,  and  the  shovels  attached  thereto.  The 
four-shovel  cultivator  is  adapted  to  deep  cultivation; 
the  six  and  eight  to  more  shallow  cultivation,  covering  the 
space  between  the  rows  more  thoroughly  but  less  deeply. 
With  a  large  number  of  shovels  and  shanks,  the  gangs 
become  easily  clogged  with  trash  if  the  ground  is  not  entirely 
free  from  it.  A  compromise  is  represented  by  the  six-shovel 
cultivator,  which  is  the  most  popular  throughout  the  corn 
belt. 

The  cultivator  beams  are  now  quite  generally  made  of 
steel,  although  wooden  beams  may  be  purchased.     Although 


FARM  MACHINERY  239 

slightly  heavier,  the  steel  beam  is  not  so  easily  clogged  with 
trash.  The  shanks  may  also  be  of  steel  or  wood,  with  the 
same  advantages.  A  break-pin  device  or  a  spring  trip 
should  be  provided  to  prevent  breakage  of  the  shank  if  a 
root  or  stone  be  struck  by  the  shovels.  The  best  cultivator 
shovels  are  made  of  soft-center  steel  hardened  so  as  to 
take  a  bright  polish. 

The  widths  of  the  shovels  vary  from  two  to  four  inches, 
and  the  wider  shovels  may  be  twisted  so  as  to  assist  in  throw- 
ing the  furrow  to  one  side.  The  straight  shovels  are  adjust- 
able upon  their  shanks  to  accomplish  the  same  results. 
Where  shallow  cultivation  is  desired  without  a  surface  culti- 
vator, the  spring-tooth  cultivator,  with  four  to  eight  small 
teeth  mounted  upon  springs,  is  successfully  used. 

The  coupling  of  the  beam  to  the  frame  io  one  of  the  most 
important  features  of  the  cultivator,  for  it  must  enable  the 
beam  to  be  shifted  horizontally  and  vertically  and  at  the 
same  time  cause  the 
shovels  to  remain  in  a 
vertical  position.  In 
order  that  this  part  of 
the  cultivator  shall  ren- 
der long  service,  due 
provision  must  be 
made  for  adjustment 
for  wear. 

The    gangs    should 

■t  J         J  A.t.        i.        -T   Jg.        J.10.  .rt.       I  lUlllB       UUlLlVtlUJI        Will 

be     so     SUSpendea    that  frame  and  hammock  seat. 

they  will   swing   in    a 

horizontal  plane  and  not  be  lifted  from  the  ground  when 
swung  to  one  side.  Since  there  is  a  tendency  to  advance 
the  shovels  as  they  are  swung  to  either  side,  it  is  easy  to  see 
why  a  long  beam  is  more  easily  guided  than  a  short  one. 


240  AGRICULTURAL  ENGINEERING 

As  the  long  beam  is  swung  to  one  side  it  does  not  advance 
so  much,  because  it  travels  in  the  arc  of  a  larger  circle. 

Due  provision  should  be  made  for  varying  the  width 
between  the  gangs  to  suit  the  various  conditions  which  may 
arise.  This  adjustment  should  be  easily  and  quickly  accom- 
pUshed.  The  wheels  should  also  be  adjustable  to  various 
widths.  Many  cultivators  are  now  made  with  reversible 
axles;  that  is,  the  axles  are  made  in  the  form  of  the  letter  Z; 
one  of  the  two  ends,  which  are  alike,  is  attached  to  the  culti- 
vator and  the  other  end  serves  as  the  axle  proper.  After 
the  one  becomes  worn,  the  ends  may  be  reversed  and  a  new 
wearing    surface    presented. 

Wheels.  The  wheels  of  a  cultivator  should  be  high  and 
have  wide  tires  which  will  not  carry  dirt  up  on  the  inside. 
Often  the  value  of  a  cultivator  is  indicated  by  the  construc- 
tion of  the  wheels.  To  determine  their  strength,  the  width 
and  thickness  of  the  tires  and  the  number  and  diameter 
of  the  spokes  should  be  observed.  The  wheels  should  have 
interchangeable  boxes  which  may  be  replaced  after  they  are 
worn  without  requiring  an  entirely  new  wheel,  and  these 
boxes  should  be  dustproof  or  long  distance.  To  describe, 
the  wheel  is  held  in  place  by  a  collar  on  the  inside  arranged 
to  exclude  the  dirt  and  dust,  and  the  outer  end  of  the  wheel 
box  is  enclosed.  The  end  of  the  wheel  box  had  best  be  remov- 
able for  fining  with  axle  grease  or  hard  oil.  A  supply  of 
grease  in  one  of  these  inclosed  boxes  will  last  for  a  long  time. 

Balance  Frame.  The  balance  frame  now  generally  used 
on  cultivators  has  two  purposes;  first  to  balance  the  weight 
of  the  operator  on  the  wheels;  and,  second,  to  balance  the 
cultivator  when  the  gangs  are  carried  out  of  the  ground. 
The  balance  frame  makes  provision  for  setting  the  wheels 
forward  or  backward  as  required.  It  should  be  a  feature 
of  every  riding  cultivator. 


FARM  MACHINERY  241 

Guiding  Devices.  To  guide  or  steer  cultivators,  the 
tongue  or  the  wheels  are  often  pivoted  and  connected  to 
levers  in  such  a  way  as  to  be  conveniently  operated. 
The  'pivoted  tongue  enables  the  operator  to  vary  the  angle 
with  which  the  tongue  is  attached  to  the  cultivator.  The 
tongue  may  be  attached  to  a  treadle  to  be  worked  by  the  feet 
and  used  continually  for 
guiding  the  cultivator,  or 
it  may  be  attached  to  a 
lever,  permitting  adjust- 
ment for  hillsides  or  for 
the  team  when  they  can- 
not be  driven  true  to 
the  row. 

(.77  ^*^-     '^^^'      -^    two-row     cultivator    with 

Some  form   of   treadle    straddle  seat  placed  well  to  the  rear.    The 
.  -  ,  •11     gangs  are  guided  by  a  treadle  device. 

guide  must  be  provided 

with  the  two-row  cultivators,  as  it  is  not  possible  to  guide 
each  pair  of  gangs  independently.  The  treadle  guide  may  be 
attached  to  the  gangs  only,  or  it  may  govern  the  direction  of 
wheels  at  the  same  time.  It  is  claimed  that  this  double 
arrangement  requires  less  effort  on  the  part  of  the  operator, 
for  it  is  only  necessary  to  change  the  direction  of  the  wheels 
and  the  team  must  do  the  work.  On  the  other  hand,  the 
shifting  of  the  gangs  alone  gives  a  much  quicker  action. 

Seats.  The  seat  of  the  riding  cultivator  is  made  in  two 
forms,  the  straddle  seat  and  the  hammock  seat.  The  first 
is  placed  upon  a.  stiff  arm  extending  back  from  the  frame, 
and  the  second  has  the  seat  suspended  on  a  metal  strap  be- 
tween two  arms  extending  back  from  the  frame.  The  stradle 
seat  is  more  rigid  and  is  universally  used  on  lever  and  treadle- 
guided  cultivators.  The  hammock  seat  offers  a  good  oppor- 
tunity to  operate  the  gangs  with  the  feet,  as  the  seat  support 
is  not  in  the  way. 


242 


AGRICULTURAL  ENGINEERING 


Fig.  150.     A  surface  cultivator. 


anything  but  satisfactory. 


Surface  Cultivators.    The  surface  cultivator  is  apparently 
gaining  favor  throughout  the  corn  belt.     It  is  provided  with 

long  flat  shovels  which  shave 
the  ground  from  one  to  two 
inches  below  the  surface,  cut- 
ting off  the  weeds  and  pulver- 
izing the  surface.  The  sur- 
face cultivator  is  a  special 
implement.  It  has  been  the 
author's  experience  that  go- 
pher or  surface  shovels  at- 
tached to  the  shovel  cultivator 
with  an  extra  arch  between  are 
It  is  quite  necessary  that  the 
gangs  be  of  very  rigid  construction  or  the  shovels  will  not 
run  at  an  even  depth  and  will  not  be  easily  controlled. 
The  surface  cultivator 
will  work  satisfactorily 
only  where  the  ground  is 
in  good  tilth  and  free 
from  trash. 

The  Disk  Cultivator. 
The   disk    cultivator    is 
preferred  by  some  corn 
growers.    It  is  generally 
used  in  connection  with 
the  weeder  or  for  Usted 
corn,  as  it  moves  consid- 
erable  soil  in  one  .direction,   either   to   or  from  the  corn. 
Strength  and   durabihty  of  the  parts,  especially  the  bear- 
ings, are  the  important  things  to    consider  when   making 
a  selection. 


Fig.  151.     A  disk  cultivator. 


FARM  MACHINERY  243 

QUESTIONS 

1.  Trace  the  development  of  the  cultivator. 

2.  What  are  some  of  the  factors  which  should  be  considered  in  mak- 
ing a  selection  of  a  cultivator? 

3.  What  direct  and  indirect  advantages  has  the  riding  cultivator 
over  the  walking  cultivator? 

4.  Describe  the  construction  of  the  tongueless  walking  cultivator. 

5.  Describe  some  of  the  important  features  of  modern  cultivators. 

6.  What  can  you  say  of  the  various  shovel  equipments  for  culti- 
vators? 

7.  Describe  a  good  method  of  suspending  the  gangs. 

8.  What  adjustment  should  be  provided  in  the  cultivator? 

9.  What  is  the  purpose  of  the  balance  frame? 

10.  What  is  the  difference  between  a  pivoted  tongue  and  pivoted 
wheels? 

11.  What  two  types  of  seats  are  used  on  cultivators? 

12.  Describe  the  construction  of  the  surface  cultivator. 

13.  To  what  use  may  the  disk  cultivator  be  put? 


CHAPTER  XXXVII 
THE  GRAIN  BINDER  OR  HARVESTER 

Of  all  the  machines  which  have  been  invented  and  de- 
veloped during  the  past  century,  perhaps  none  has  been  the 
means  of  saving  more  labor  than  the  modern  grain  binder. 
It  has  been  the  main  factor  in  reducing  the  amount  of  labor 
required  to  produce  a  bushel  of  wheat  from  three  hours  to 
ten  minutes,  and  at  the  same  time  has  greatly  improved  the 
quality  of  the  product. 

The  grain  binder  has  undergone  little  change  in  the  last 
ten  years,  nor  is  there  any  important  improvement  proposed 
or  desired  at  the  present  time.  The  test  of  time  has  elimi- 
nated from  the  field  the  unsatisfactory  machines,  in  spite  of 
the  fact  that  the  binder  is  a  very  complicated  machine  and 
must  often  do  its  work  under  very  adverse  circumstances. 
For  these  reasons  this  chapter  will  be  a  discussion  primarily 
of  the  adjustments  of  the  binder. 

Size.  Formerly  the  standard  binder  was  a  5-,  6-,  or  7-foot 
cut  machine.  More  recently,  by  the  use  of  tongue  trucks 
to  care  for  the  side  draft,  the  8-foot  machine  has  become 
popular  among  farmers  who  have  large  areas  of  grain  to  cut. 
Under  favorable  conditions  and  with  large  areas  the  push 
binder  of  10-,  12-,  or  14-foot  cut  may  be  used  economically. 
These  machines  require  at  least  six  horses,  and  four  horses 
are  generally  used  on  the  eight-foot-cut  machines. 

Selection.  Convenience  and  proper  range  of  adjust- 
ment, and  adequate  means  of  lubrication  are  the  important 
things  to  keep  in  mind  in  selecting  a  binder.  The  variety 
of  grains  harvested  with  the  grain  binder  requires  a  wide  range 
of  adjustment. 

244 


FARM  MACHINERY 


245 


246  AGRICULTURAL  ENGINEERING 

Tongue  Trucks.  The  tongue  truck  is  one  of  the  newer 
attachments  for  the  binder,  and  is  a  device  which  is  highly 
satisfactory,  especially  on  the  wide-cut  machines.  It  is 
quite  impossible  with  these  wide  machines  to  arrange  the 
hitch  in  such  a  way  as  to  overcome  side  draft.  The  tongue 
truck  is  the  only  satisfactory  method  of  relieving  the  horses 
of  this  burden. 

Engine  Drive.  It  has  become  a  quite  common  practice 
of  late  to  mount  a  small  gasohne  engine  upon  the  binder  to 
drive  the  machinery,  reUeving  the  horses  of  all  work  except 


CANVASS  OR  APROH 
ELEVATOR 


*TWINE  BOX 
/Ns^~~:~: XuTATonHM  — — ^  ^DRIVE  WHEEL 

Fig.    153.      The   harvester   shown   in   Fig.    152,    with   some   of   the   parts 

named. 

that  required  in  drawing  the  machine  on  its  wheels.  This 
makes  it  possible  to  save  a  crop  on  wet,  soft  ground  where 
an  ordinary  binder  would  fail  because  the  main  wheel  will 
slip.  In  extreme  cases  the  binder  has  been  successfully 
mounted  upon  skids  or  sled  runners  and  used  to  save  a  crop 
where  the  soil  was  so  wet  and  sticky  that  the  main  wheel  of 
the  binder  would  become  so  thoroughly  filled  with  mud  as 
to  refuse  to  revolve. 

Operation  of  Binders.    It  should  be  the  pride  of  every 
binder  operator  to  so  manage  and  adjust  his  machine  that 


FARM  MACHINERY  247 

perfect,  well-bound  bundles  will  be  formed  and  tied.  To 
procure  such  bundles,  attention  must  first  be  given  to  the 
adjustment  of  the  reel,  which  should  so  catch  and  deliver 
the  standing  grain  that  it  will  fall  evenly  and  squarely  upon 
the  platform  apron  or  canvas.  If  the  grain  is  straight  and 
standing  well,  the  reel  should  be  set  far  enough  ahead  and 
low  enough  that  the  grain  will  be  slightly  bent  back  over  the 
platform  when  cut  off.  This  will  cause  it  to  fall  directly 
back  at  right  angles  to  the  cutter  bar.  Often  the  grain  varies 
in  height  in  different  parts  of  the  field,  and  adjustment  of 
the  reel  should  be  made  from  time  to  time  while  the  machine 
is  in  motion. 

Again,  the  proper  adjustment  of  the  binder  attachment 
and  the  butt  adjuster  canvas  should  not  be  overlooked. 
In  all  machines  these  two  parts  are  adjustable.  The  binder 
attachment  may  be  sUd  forward  and  backward,  enabling 
the  operator  to  place  the  band  nearer  the  head  or  the  butt  of 
the  bundles  as  he  may  desire.  In  hke  manner,  the  butt  ad- 
juster may  be  set  so  as  to  push  or  pat  the  straw  into  an  even 
bundle  at  the  butt  end  and  to  push  the  straw  back  more  or 
less  as  desired. 

Sometimes  a  binder  will  give  trouble  in  tearing  the  slats 
from  the  canvas.  This  trouble  is  due  to  the  fact  that  the 
rollers  over  which  canvases  pass  are  not  parallel  or  square 
with  the  frame.  If  trouble  of  this  kind  occurs,  the  elevator 
frames  and  rollers  should  be  immediately  trued  up.  Pro- 
vision for  adjustment  is  found  on  all  machines,  and  the  car- 
penter's square  will  be  found  a  useful  means  of  securing 
accuracy. 

The  main  drive  chain  of  a  binder,  if  run  too  loosely  and  if 
dry  or  muddy,  has  a  tendency  to  chmb  the  sprocket  teeth  and, 
in  shpping  in  place  again,  give  the  machine  a  jerky  motion 
as  if  some  part  of  the  machine  were  catching  or  striking  some 


248 


AGRICULTURAL  ENGINEERING 


other  part.  This  action  makes  the  difficulty  hard  to  locate. 
It  is  easy  to  overcome  by  simply  tightening  the  chain  and  by 
oiUng. 

The  elevator  chain,  the  long  chain  which  drives  the  ele- 
vator rollers,  should  not  be  run  too  tight,  as  it  increases 
the  draft  and  the  wear  of  the  parts.  Machines  are  some- 
times greatly  damaged  in  a  short  time  by  running  this  chain 
too  tight. 

Adjustment.  To  make  bundles  of  the  proper  size,  the 
binder  is  provided  with  a  clutch  which  is  placed  in  gear  by 
the  trip  when  sufficient  grain  has  been  gathered  by  the 
packers  to  form  a  bundle.  If  the  spring  which  holds  the 
clutch  pawl,  or  dog,  in  place  be  lost  or  broken,  the  clutch  will 
not  be  positive  in  its  action  and  will  form  undersized  bundles. 
If  larger  or  smaller  bundles  are  desired,  the  bundle-sizer 
spring  should  be  adjusted,  and  not  the  compress  spring  or 
the  spring  connected  with  the  needle  shaft.  The  latter  spring 
is  used  to  relieve  the  strain  upon  the  parts,  and  should  not  be 
made  too  tight. 

Causes  of  Failure  to  Tie.  The  part  of  the  binder  which 
requires  the  most  careful  adjustment  is  the  tying  mechanism. 
Mention  can  only  be  made  here  of  a  few  misadjustments  and 
their  symptoms.  It  is 
customary  for  those  who 
practice  binder  experting 
to  examine  the  band  that 
comes  from  the  machine 
when  the  machine  fails 
to  tie.  Often  the  ends 
of  the  twine,  whether 
frayed  or  cut  off  clean, 
the  kinks  in  the  t^vine,  or  the  knot,  if  there  should  be  one 
in  one  end  of  the  band,  will  indicate  at  once  the  cause  of 


The    tying  mechanism   of 
modern  binder. 


FARM  MACHINERY 


249 


the  failure  to  make  a  complete  knot.  The  names  of  the 
various  parts  of  the  tying  mechanism  may  be  learned  from 
the  accompanying  illustration.  If  the  needle  does  not  carry 
the  twine  over  far  enough,  the  twine  disk,  or  cord  holder, 
will  grasp  only  one  strand,  and  the  knot  will  be  tied  only 

in  one  end  of  the  cord, 
with  the  other  extending 
back  to  the  machine. 
This  condition  is  shown 
in  No.  1,  Fig.  155,  and 
may  be  caused  occasion- 
ally by  a  straw  interfer- 
ing with  the  placing  of 
the  twine. 

When  the  twine  disk 
is  too  tight,  the  symp- 
toms will  be  much  Hke 
those  just  described,  ex- 
cept that  one  end  of  the 
band  will  be  frayed  (No. 
2,)  indicating  that  it  has 

Pig.  155.  The  ends  of  bands  which  have  -i.--^  „,,+  --£p  i...  U^:^„ 
not  been  made  into  perfect  knots.  (After  DCen  CUL  OH  Oy  DCmg 
Steward  in  Trans.  Am.  Soc.  A.  E.;  pmched    tOO  tightly    and 

that  the  spring  should  be  loosened.  If  both  ends  are  cut 
off  irregularly,  as  shown  in  No.  3,  it  is  quite  a  sure  sign 
that  the  holder  is  too  tight. 

If  the  knotter  spring,  which  holds  the  finger  down  upon  the 
knotter  hook,  is  too  loose  and  does  not  hold  the  ends  of 
the  twine  while  the  knot  is  pulled  over  the  hook  forming  the 
knot,  the  ends  of  the  band  will  appear  as  shown  in  No.  4. 
The  same  kind  of  band  is  found  when  the  knife  cuts 
the  twine  too  soon  before  the  knotter  finger  has  closed 
over  it. 


250  ACFRICULTURAL  ENGINEERING 

If  the  needle  has  become  bent  or  the  pitman  which 
actuates  it  worn  until  the  needle  does  not  place  the  twine 
squarely  over  the  notch  in  the  twine  holder,  a  loose  band 
will  be  produced  as  shown  in  No.  5,  Fig.  155;  that  is,  there 
will  be  a  knot  in  one  end,  and  the  other  end  will  be  cut  off 
squarely  but  without  a  kink  in  it. 

If  the  needle  of  the  modern  binder  becomes  slightly 
bent,  it  may  be  hammered  back  without  fear  of  breakage. 

QUESTIONS 

1.  Why  is  the  grain  binder  an  important  machine? 

2.  In  what  sizes  are  grain  binders  manufactured? 

3.  What  are  the  important  features  involved  in  the  selection  of  the 
grain  binder? 

4.  To  what  use  may  the  tongue  truck  be  put? 

5.  When  may  the  machinery  of  the  harvester  be  driven  with  a 
gasoline  engine  to  good  advantage? 

6.  To  what  purpose  should  the  binding  mechanism  of  the  harvester 
be  adjusted? 

7.  How  should  the  elevator  rollers,  main  and  elevator  chains  be 
adjusted  on  a  binder? 

8.  What  adjustment  should  be  made  to  change  the  size  of  the 
bundles? 

9.  Explain  five  causes  for  failure  of  the  knotter  to  tie  a  knot. 


CHAPTER  XXXVIII 
CORN  HARVESTING  MACHINES 

Sled  Com  Cutter.  These  machines  are  arranged  with 
stationary  knives  set  at  an  angle  on  the  edge  of  a  platform 
and  at  such  a  height  that  the  standing  stalks  will  be  cut  off 
as  they  are  grasped  in  the  arms  of  the  operator  standing 
or  sitting  upon  the  platform.  The  machine  is  mounted 
either  upon  sled  runners  or  upon  low  wheels  and  is  drawn 
by  one  or  two  horses.  When  an  armful  of  stalks  has  been 
collected,  a  stop  is  made  and  the  corn  laid  in  piles  or  is 
shocked  at  once.  These  sled  cutters  are  often  homemade 
and  are  constructed  in  a  variety  of  shapes  and  forms. 

Several  machines  have  been  devised  with  arms  and  other 
mechanism  to  assist  in  gathering  the  stalks;  but  these  ma- 
chines, although  quite  successful,  have  not  come  into  extend- 
ed use,  owing  perhaps  to 
the  fact  that,  if  a  more 
expensive  machine  were 
desired  than  the  simple 
sled  harvester,  the  corn 
binder  would  be  pur- 
chased. 

Fig.   156.     A  sled  corn  harvester. 

It  has  been  found 
that  the  average  acreage  harvested  in  a  day  by  two  men 
and  one  horse  with  a  sled  harvester  was  4.67  acres,  the 
amount  ranging  from  2  to  10  acres.  This  variation  is  un- 
doubtedly due  largely  to  the  weight  and  condition  of  the  corn. 
The  sled  harvester  cannot  be  used  successfully  in  extremely 
heavy  corn  or  in  corn  which  does  not  stand  upright. 

2.51     _/ 


252 


AGRICULTURAL  ENGINEERIJSJU- 


The  Com  Binder  or  Harvester.  Because  of  the  general 
introduction  of  the  silo,  the  corn  binder  is  used  more  than 
ever  before.  In  filling  the  silo  the  corn  must  be  cut  rapidly, 
and  besides  it  is  much  more  conveniently  handled  when 
bound  into  bundles.  When  the  corn  is  shocked,  the  use  of 
the  harvester  will  not  show  much  economy  over  cutting  by 
hand;  this,  however,  is  disagreeable  work,  and  the  use  of  the 


Fig.    157,      A   corn   harvester   of   the   vertical    type   at   work. 


machine  is  to  be  commended  because  it  does  away  with 
much  of  it. 

Results  of  an  investigation  of  corn  harvesting  methods  *  show 
that  the  average  acreage  cut  per  day  with  a  binder  was  7.73 
acres.  The  average  life  of  the  corn  harvester  was  8.17  years, 
cutting  on  an  average  a  total  of  668.77  acres.  The  amount 
of  twine  used  per  acre  was  2.44  pounds,  and  one  man  was 
able  to  shock  the  corn  on  3.31  acres  in  one  day.  .  From  this 

♦Farmer's  Bulletin  303,  U.  S.  Dept.  of  Agriculture. 


FARM  MACHINERY  253 

data  the  cost  of  harvesting  and  shocking  an  acre  is  made  up 
in  the  following  items: 

Cost  of  machine  and  interest  on  investment.  . .   S.29     per  acre 

Driver  and  team 46     per  acre 

Twine 305  per  acre 

Shocking 448  per  acre 

Total  cost $1,503  per  acre 

If  a  large  acreage  is  harvested  annually,  the  cost  per  acre 
will  be  much  reduced.  In  modern  siloing  operations  the 
com  is  loaded  directly  upon  wagons,  and  the  cost  of  shock- 
ing, which  is  about  one-third  of  the  cost  as  given  above,  is 
not  incurred. 

Types  of  Com  Binders.  There  are  two  general  types 
of  corn  binders  upon  the  market:  those  which  bind  the  corn 
in  an  upright  position,  and  those  which  convey  the  cut  corn 
to  a  horizontal  deck  before  binding.  There  is  also  an  inter- 
mediate type  in  which  the  corn  is  neither  vertical  nor  hori- 
zontal, but  somewhere  between  the  two,  or  incUned.  Each 
of  these  types  is  well 
tried  out  and  is  success- 
ful, and  they  differ  but 
little  in  the  essentials  of  ^^:^  ,  ^* 
construction.  Dividers 
on  either  side  of  the  row 

gather   and  lift  the  down        Fig.    158.    "a     com    harvester    of    the 
stalks.      Chains  ^Vith  lugs  horizontal    type. 

extending  across  the  opening  between  the  dividers  carry 
the  stalks  back  to  the  binder  proper.  There  are  usually 
three  pairs  of  these  conveyor  chains,  one  pair  for  the  butts, 
one  pair  of  main  chains,  and  one  pair  for  tall  corn. 

At  least  one  machine  does  not  have  the  usual  packer 
found  on  the  others  and  on  the  grain  binder.    In  this  machine 


254  AGRICULTURAL  ENGINEERING 

the  conveyor  chains  are  made  to  extend  farther  back,  and 
during  the  time  a  bundle  is  being  tied  the  lugs  or  fingers  are 
allowed  to  fold  back,  not  forcing  the  corn  upon  the  needle. 
Three  horses  are  usually  used  with  the  corn  binder,  though 
in  heavy  corn  four  horses,  two  teams  in  tandem,  can  be  used 
to  good  advantage,  and  the  extra  power  is  much  needed. 

The  care  and  operation  of  the  corn  binder  do  not  differ 
materially  from  that  of  the  grain  binder.  The  adjustment 
of  the  tying  mechanism  is  just  the  same.  The  service 
demanded  of  the  corn  binder,  however,  is  much  more  severe, 
and  it  does  not  have  as  long  a  life  as  the  grain  binder. 

The  Com  Shocker.  The  corn  shocker  is  an  implement 
with  cutting  mechanism  very  similar  to  that  of  the  corn 
binder,  but  a  round,  horizontal  platform  with  a  center  pole 
is  provided,  and  is  made  to  revolve  and  collect  the  cut  corn 
and  form  it  into  a  shock.  When  a  shock  is  formed,  the  ma- 
chine is  stopped  and  the  shock  tied  and  then  lifted  from  the 
platform  and  swung  to  the  ground  by  means  of  a  derrick  and 
windlass.  The  fingers  which  extend  out  from  the  center 
pole  are  then  allowed  to  drop,  and  the  center  pole  is  removed 
and  returned  to  the  machine. 

This  machine  has  only  about  one-half  the  capacity  of  the 
corn  binder,  as  much  time  is  consumed  in  removing  the 
shocks.  Other  disadvantages  are,  first,  the  shocks  are  small 
and  do  not  stand  well;  and  second,  the  fodder  is  not  as  con- 
venient to  handle  as  when  bound  into  bundles.  In  favor  of 
it,  it  must  be  mentioned  that  it  is  a  one-man  machine,  and 
there  is  a  saving  in  the  cost  of  twine. 

Com  Pickers.  The  successful  corn  picker  is  one  of  the 
most  recent  of  agricultural  machines,  although  inventors 
have  been  trying  to  invent  a  machine  for  field  picking  for 
nearly  two-thirds  of  a  century.  The  mechanical  difficulties 
to  be  overcome  and  the  lack  of  an  imperative  need  for  the 


FARM  MACHINERY  255 

machine  are  the  main  reasons  why  this  machine  has  not  been 
perfected  to  the  extent  that  it  could  be  manufactured  and 
sold  in  the  usual  way. 

Construction.  As  usually  constructed,  the  corn  picker, 
sometimes  called  the  corn  picker-husker,  has  dividers  which 
straddle  a  row  of  standing  stalks  and  gather  them  into  an 
upright  position  similar  to  the  action  of  a  corn  harvester. 
Then  the  stalks  are  run  through  rollers  set  at  an  incline  and 
provided  with  spirals  in  such  a  way  that  the  stalks  are  con- 
veyed back  as  fast  as  the  machine  is  moved  forward.  These 
rollers  pinch  off  the  ears,  which  fall  into  a  conveyor  at  one 


Pig.    1  -husker  at  work. 

side  of  the  rollers  and  are  carried  to  the  husking  rolls.  These 
rolls  revolve  in  pairs,  and,  by  means  of  steel  studs  or  husking 
pins  set  in  the  rolls,  grasp  the  husks  and  pull  them  from  the 
ears.  The  husked  ears  and  the  shelled  corn  are  then 
elevated  into  a  wagon  drawn  beside  the  machine.  The 
better  machines  have  a  fan  for  blowing  out  the  chaff  and 
husks  and  saving  all  of  the  corn. 

The  corn  picker-husker  is  one  of  the  heaviest  of  field 
machines,  and  under  average  conditions  requires  five  large 
or  six  medium-large  draft  horses  to  draw  it.  A  driver  is 
required,  and  two  men  or  boys  with  teams  and  wagons  are 


256  AGRICULTURAL  ENGINEERING 

needed  to  haul  away  the  corn  as  it  is  gathered  and  husked. 
An  elevator  for  unloading  the  corn  is  quite  an  essential  part 
of  the  complete  outfit. 

There  is  naturally  much  difference  of  opinion  in  regard 
to  the  economy  in  the  use  of  the  corn  picker-husker  over 
hand  picking.  It  is  to  be  recognized  that  conditions  vary 
greatly,  and  it  is  upon  local  conditions  that  its  success  will 


Fig.  160.     A  corn  husker  and  shredder  at  work. 

depend.  The  machine,  on  account  of  its  great  weight,  can- 
not well  be  used  when  the  soil  is  wet.  Again,  the  machine 
does  not  do  its  best  work  in  corn  that  is  lodged  badly.  It 
will  not  pick  up  any  ears  not  attached  to  the  stalks. 

Com  Huskers  and  Shredders.  In  many  locaHties  the 
husker  and  shredder  is  quite  a  popular  machine,  and  it  is 
right  that  it  should  be.  As  farming  advances,  methods 
utihzing  the  entire  com  plant  are  sure  to  become  more  general. 

The  modem  husker  and  shredder  consists  in  snapping 
roils  to  remove  the  ears  from  the  fodder  as  it  is  fed  to  the 


FARM  MACHINERY 


25V 


machine,  a  shredder  head  to  reduce  the  fodder  to  fine  pala- 
table stock  feed,  husking  rolls  to  remove  the  husks  from  the 
ears,  an  elevator  to  elevate  the  husked  corn  into  a  wagon, 
and  an  elevator  or  blower  to  convey  the  shredded  fodder 


,nvriAur>e  j^«evw* 


Fig.   161.     A  section  of  a  corn  husker  and  shredder. 

away  from  the  machine.  Most  machines  have  devices  for 
saving  the  shelled  com.  Some  of  the  larger  machines  have 
band  cutters  and  self-feeders. 

The  size  of  the  husker  is  designated  by  the  number  of 
rolls.    An  eight-roll  husker  will  husk  from  25  to  80  bushels 
of  com  per  hour,  and  require  from  16  to  20  horsepower.     The 
cost  of  shredding  varies  from  $2.50  to  $6  per  acre. 
QUESTIONS 

1.  Describe  the  sled  com  harvester.     Is  it  practical? 

2.  What  are  the  principal  items  and  the  amount  of  each  in  the 
cost  of  harvesting  corn  with  the  corn  harvester? 

3.  Describe  the  two  general  types  of  corn  harvester. 

4.  Describe  the  construction  of  the  com  shocker. 

5.  Describe  the  construction  of  the  com  picker-husker. 

6.  Where  may  the  picker-husker  be  used  to  the  best  advantage? 

7.  What  can  you  say  of  the  economy  of  the  husker  and  shredder? 

8.  Describe  the  construction  of  the  corn  husker  and  shredder. 

9.  How  are  the  sizes  of   huskers  and  shredders  designated,  and 
what  is  the  capacity  of  the  various  sizes? 


CHAPTER  XXXIX 

HAY-MAKING  MACHINERY 
MOWERS 

The  modem  mower  has  become  a  standard  machine,  and 
the  various  makes  differ  in  details  only.  Inventors  have 
devised  many  styles  of  cutting  machines,  but  all  have  given 
way  to  the  reciprocating  knife  which  acts  between  guards  or 
fingers,  giving  a  shear  cut. 

T3rpes.  The  center  draft  mower,  with  the  cutting  bar 
directly  behind  the  team  and  in  front  of  the  driving  wheels, 
is  manufactured  in  a  limited  way.  The  main  advantage  of 
this  type  of  machine  seems  to  be  that  the  team  does  not  walk 
over  the  new-mown  grass  and  tramp  it  into  the  stubble 
This  advantage  is  offset  by  the  convenience  of  the  side  cut 
machine,  the  type  in  general  use. 

Size.  Mowing  machines  may  be  secured  in  almost  any 
size  from  the  one-horse  mower  of  33^-  or  4-foot  cut  to  the 
8-foot-cut  machine.  The  4}^-  and  5-foot  cuts  are  known  as 
the  standard  machines,  and  the  6-foot  cut  as  the  standard 
wide-cut  machine.  The  wide-cut  machine  is  usually  made 
somewhat  heavier  than  the  standard  machines,  yet  they  are 
adapted  only  to  certain  conditions  where  the  service  consists 
largely  in  straight  meadow  mowing. 

Construction  of  Mowers.  The  weight  of  a  mower 
determines  to  some  extent  its  driving  power,  but  this  is  also 
increased  by  the  design  of  the  wheels  and  the  distribution 
of  the  weight.  The  drive  wheels  should  be  high  and  have 
broad  tires.     The  usual  widths  of  tires  are  33^  and  4  inches. 

258 


FARM  MACHINERY 


259 


It  is  best  that  the  wheels  be  placed  far  apart,  as  this  makes 
a  better  balanced  machine  as  far  as  draft  and  driving  power 
are  concerned. 

The  main  shaft  should  be  a  smooth  or  "cold  rolled"  shaft 
throughout  its  entire  length,  and  should  be  of  liberal  size. 
Roller  bearings  for  the  main  shaft  are  desirable,  as  they  not 
only  reduce  friction  but  also  prevent  any  binding  of  the  shaft 
in  the  frame  and  furnish  a  good  reservoir  for  a  supply  of  oil. 
It  is  well  that  the  wheels  be  provided  with  a  sufficient  number 
of  pawls  to  engage  the  axle  ratchets  without  much  lost 
motion.  There  should  be  Httle  lost  motion  throughout 
the  entire  mechanism,  as  it  is  highly  desirable  to  have  the 
knife  start  as  soon  as  the  drivers  and  prevent  the  guards  from 
becoming  clogged. 

There  is  at  the  present  time  a  considerable  difference  in 
the  size  of  the  gears  used  in  mowers.    Besides  being  strong 


Fig.    162.      A    modi  rn    mower   at    work 


260        -  AGRICULTURAL  ENGINEERING 

enough,  these  gears  should  be  of  Uberal  dimensions,  especially 
in  width,  to  resist  wear.  It  is  an  advantage  to  have  the  gears 
so  arranged  that  the  thrust  which  exists  between  separate 
pairs  of  gears  shall  balance  as  far  as  possible. 

Due  provision  should  be  made  to  keep  the  gears  well 
lubricated  and  well  protected  from  dust.  There  is  no  good 
reason  why  the  gears  of  mowers  should  not  be  arranged  to 
run  in  oil,  although  this  is  not  practiced. 

The  small,  fast-moving  gear  pinion  is  the  first  to  wear 
out,  and  the  construction  of  the  mower  should  be  such  as 
to  permit  this  pinion  to  be  easily  replaced.  There  is  con- 
siderable end  thrust  on  the  crank  shaft  upon  which  the  bevel 
gear  pinion  is  placed,  owing  to  the  tendency  for  the  gears  to 
force  themselves  apart.  This  end  thrust  should  be  carefully 
provided  for.  Some  of  the  best  mowers  upon  the  market 
are  made  with  a  ball-thrust  bearing.  Other  mowers  have 
hardened  steel  washers  to  take  the  wear,  and  in  any  case 
there  should  be  means  of  adjusting  for  wear. 

The  chain  drive  mower  is  used  to  some  extent  at  the  pres- 
ent time,  but  not  as  much  as  formerly.  There  are  at  least 
two  disadvantages  of  the  chain-drive  mower,  in  which  one 
pair  of  gears  is  replaced  by  a  pair  of  sprokets  and  a  chain  or 
link  belt;  first,  it  is  not  as  positive  in  action  as  the  gears;  and, 
second,  the  chains  do  not  seem  to  be  as  durable  as  the  gears. 

Usually  mowers  have  but  two  pairs  of  gears,  but  some 
mowers  have  three.  No  serious  objections  can  be  made  to 
the  latter.  At  least  one  make  has  two  speeds  for  the  knife, 
obtained  by  changing  gears.  The  lower  crank  end  of  the 
crank  shaft  should  have  a  bearing  which  will  permit  adjust- 
ment for  wear.  One  of  the  most  common  methods  of  mak- 
ing this  adjustment  is  to  replace  an  interchangeable  brass 
bush  used  as  the  bearing  Uning.  In  mowers  there  is  an 
adjustable  cap  to  the  bearing,  which  may  be  adjusted  by 


FARM  MACHINERY  261 

means  of  the  bolts  which  hold  it  in  place  and  by  the  use  of 
liners  under  the  edges  of  the  cap. 

It  is  to  be  expected  that  the  severest  wear  will  come  upon 
the  pitman.  The  pitman  bearings  are  difficult  to  lubricate. 
A  mower  which  does  not  provide  for  adjustment  and  replace- 
ment of  the  wearing  parts  of  the  pitman  and  crank  is  not 
modem.  Owing  to  the  difficulty  of  keeping  adjustable  parts 
tight,  the  crank  pin  box  is  usually  made  of  soUd  metal,  lined 
with  brass  or  babbitt,  and  capable  of  being  replaced  at  small 
expense. 

Provision  is  made  in  every  modern  mower  for  the  replace- 
ment of  the  wearing  parts  of  the  cutting  mechanism  and  for 
their  adjustment  to  the  fullest  extent.  This  statement  refers 
to  the  sickle  or  the  sec- 
tions of  it;  the  guards  or 
their  ledger  plates,  which 
provide  one-half  of  the 
cutting  edges;  the  clips 
which  hold  the  knife 
over  the  ledger  plates; 

J.I  .  -1    J.  Fig.    163.      A    side-draft    mower. 

and  the  wearmg  plates 

which  support  the  rear  edge  of  the  sickle.  All  of  these 
parts  are  subject  to  rapid  wear,  and  even  when  made  of  the 
best  materials  they  must  be  replaced  several  times  during 
the  life  of  the  mower.  It  is  not  an  uncommon  matter  to 
find  that  a  mower  has  been  discarded  when  it  could  be  made 
practically  as  good  as  new  by  the  replacement  of  parts  whose 
cost  is  but  a  small  part  of  the  whole. 

The  cutter  bar  of  a  mower  should  be  carried  as  far  as  pos- 
sible upon  the  main  truck,  in  order  to  reduce  the  draft  due 
to  dragging  the  bar.  This  is  usually  accomplished  by  suit- 
able linkage  and  springs  which  may  be  adjusted  in  such  a 
manner  as  to  carry  all  of  the  weight,  except  enough  to  keep 


262 


AGRICULTURAL  ENGINEERING 


the  cutter  bar  to  the  surface  of  the  ground.  A  draft  rod 
direct  from  the  doubletrees  to  the  cutter  bar  assists  in  lower- 
ing the  draft,  and  is  universally  used  on  modern  mowers. 
Adjustments  of  the  Mower.  The  adjustments  of  the 
mower  are  of  the  greatest  importance.  First,  the  cutter  bar 
should  be  in  alignment,  or  should  extend  out  to  the  side  of 
the  mower  at  right  angles  to  the  crank  shaft.  If  not  in  per- 
fect ahgnment,  the  pitman  will  be  cramped,  increasing  the 
wear,  if  not  causing  early  breakage.  There  is  sure  to  be 
more  or  less  wear  in  the  hinge  joints  of  the  cutter  bar,  and 


Fig.    164. 


An   illustration   showing    the    proper   adjustment   of   the 
cutter  bar. 


an  adjustment  must  be  made  for  this  wear  from  time  to  time. 
The  device  for  aligning  the  cutter  bar  differs  in  each  type  of 
mower,  yet  it  is  to  be  found  in  all  good  mowers. 

Secondly,  the  knife  should  be  made  to  register,  or  to  travel 
equally  over  the  guards  at  the  ends  of  the  stroke.  Misadjust- 
ment  in  this  respect  is  often  the  cause  of  failure  to  cut  proper- 
ly. The  method  of  adjustment  varies  with  different  mowers. 
In  some  the  length  of  the  pitman  is  changed;  in  others,  the 
length  of  the  drag  bar.  It  is  also  true  that  many  mowers 
do  not  offer  a  ready  means  of  adjustment. 


FARM  MACHINERY  263 

The  sickle  must  be  so  adjusted  under  the  clips  that  each 
section  will  form  a  shear  cut  with  the  ledger  plates.  The 
chps  which  hold  the  knife  down  are  made  of  malleable  iron  or 
steel  and  are  adj  usted  by  bending  down  with  a  hammer.  They 
must  not  be  too  tight;  there  should  be  a  httle  clearance  be- 
tween the  knife  and  the  ledger  plates  about  equal  to  the 
thickness  of  ordinary  paper.  The  guards  must  all  be  in  line 
so  that  the  above  adjustment  will  be  possible.  Bent  guards 
may  be  hammered  back  into  line,  as  they  are  made  of  malle- 
able iron  and  are  not  easily  broken.  The  aHgnment  should 
be  tested  by  sighting  over  the  ledger  plates.  If  the  mower 
leaves  streaks  of  long  stubble,  and  the  knife  is  in  good  con- 
dition, it  is  quite  a  sure  indication  that  one  or  more  of  the 
guards  have  been  bent  out  of  line.  The  rear  of  the  knife  is 
supported  by  steel  wearing  plates  which  assist  in  keeping  the 
points  of  the  sections  down  over  the  guards.  If  these  become 
worn  until  they  no  longer  keep  the  knife  in  place,  new  ones 
must  be  put  in,  which  may  be  done  at  small  expense. 

The  sickle  should  be  kept  sharp  at  all  times.  It  is  poor 
economy  to  use  a  dull  knife,  owing  to  the  increase  of  wear 
upon  the  machine  and  the  poor  quaUty  of  work  which  is  sure 
to  be  performed.  All  nicked  or  broken  sections  which  can 
not  be  sharpened  should  be  replaced.  If  many  of  the  sections 
are  damaged,  it  is  best  to  buy  an  entirely  new  knife. 

HAY  RAKES 

The  Sulky  Rake.  The  sulky  rake  is  made  either  to  be 
dumped  by  hand  or,  by  engaging  a  pawl  on  the  tooth  bar  with 
a  suitable  ratchet  on  the  wheels  or  axle,  the  machine  is  made 
self-dumping.  The  self-dump  rake  costs  but  Uttle  more 
than  hand-dump  and  has  the  additional  advantages. 

In  selecting  a  sulky  rake  one  need  consider  only  the  size 
and  spacing  of  teeth  to  suit  the  conditions  to  be  met.     The 


264 


AGRICULTURAL  ENGINEERING 


teeth  are  made  in  two  sizes,  of  %  6-inch  and  3^-inch  round  steel, 
with  one  or  two  coils  at  the  top  to  give  more  or  less  elasticity 
and  with  either  pencil  or  chisel  points.  The  teeth  are  spaced 
from  33^  to  5  inches  apart.     The  heavier  rakes  are  used  for 


A  modern  stlf-dump  sulky  rake   at  work. 


the  heavier  crops  like  alfalfa  and  sorghum.  A  rake  should 
be  so  constructed  as  to  be  easily  dumped  and  to  thoroughly 
clean  itself. 

Side-delivery  Rakes.  The  side-delivery  rake  has  much 
the  same  function  as  the  tedder.  Instead  of  merely  turning 
the  hay,  however,  the  side-dehvery  rake  has  a  revolving 
toothed  cyUnder  acting  in  the  opposite  direction  and  set  at 
such  an  angle  as  to  deliver  the  hay  to  one  side  in  a  loose, 
fluffy  windrow  through  which  the  air  can  circulate  readily. 
Where  the  hay  is  light,  it  is  put  in  good  shape  for  the  hay- 


FARM  MACHINERY  265 

loader.     Where  the  hay  is  extremely  light,  two  windrows 
may  be  thrown  together. 

There  is  much  difference  in  the  mechanism  of  the  side- 
deUvery  rakes.  In  general,  there  are  two  types:  (1)  the  one- 
way rake,  which  has  revolving  forks  to  throw  the  hay  to  one 
side  into  a  windrow;  and  (2)  the  reversible  rake,  which  gathers 
the  hay  and  conveys  it  onto  an  endless  apron  across  the  ma- 
chine and  which  may  be  driven  in  either  direction.  The  first 
type  is  in  more  general  use  and  is  the  cheaper  machine. 


Fig.   166.     A  three-bar  side-delivery   rake  at  work. 


The  fork  machine,  which  is  much  like  the  tedder  except 
that  the  forks  are  set  in  an  oblique  row  and  throw  the  hay 
forward  and  to  one  side,  are  preferred  by  many  practical  hay 
growers.  Cylinder  rakes,  with  teeth  to  catch  the  hay  and 
roll  it  to  one  side,  have  the  advantage  of  simpUcity,  but  the 
rolling  action  given  to  the  hay  tends  to  make  it  into  a  close, 
compact,  rope-Uke  windrow  through  which  the  air  does  not 
circulate  as  readily  as  it  might.    Many  of  the  fork  machines 


266  AGRICULTURAL  ENGINEERING 

are  so  arranged  that  the  direction  of  the  throw  of  the  forks 
may  be  reversed  and  the  rake  used  as  a  tedder. 

HAY  LOADERS 

Where  hay  is  stored  in  the  barn,  the  modern  hay  loader 
is  almost  indispensable,  as  its  use  will  pay  for  itself  in  the 
saving  of  labor  in  one  or  two  seasons.  In  general,  there  are 
two  types  of  hay  loaders:  the  fork  loader  and  the  endless- 
apron  or  carrier  loader.    The  first  of  these  is  of  simpler  con- 


Fig.  167.    A  fork  hay  loader  at  work. 

struction  and  is  a  machine  that  forces  the  hay  well  onto  the 
load. 

The  endless-apron  loaders  have  one  main  advantage,  and 
that  is  they  do  not  agitate  the  hay  severely  and  do  not  tend 
thereby  to  shake  off  the  dry  leaves.  This  advantage  apphes 
only  in  the  handling  of  such  crops  as  clover,  alfalfa,  and 
others  whose  leaves  are  easily  shaken  off.  The  endless- 
apron  machine  does  not  force  the  hay  onto  the  load  readi- 
ly, for,  when  the  hay  is  allowed  to  pile  up  at  the  end  of  the 
loader,  the  apron  tends  to  drag  the  hay  back.  At  least  one 
loader  has  been  brought  out  recently  with  the  apron  above 
the  hay  instead  of  below,  in  an  attempt  to  overcome  this 


FARM  MACHINERY  267 

difficulty.  In  selecting  a  loader,  it  would  be  well  to  see  that 
it  will  pick  up  the  hay  cleanly,  either  from  the  swath  or  the 
windrow;  will  pass  over  the  obstructions,  and  at  the  same  time 
will  not  pick  up  old  trash  which  may  be  on  the  surface  of  the 
ground.  The  loader  is  made  largely  of  wood  in  the  form  of 
light  strips,  and  for  that  reason  should  be  carefully  housed 
when  not  in  use. 

HAY  TEDDERS 

Modern  haying  methods  demand  that  the  hay  be  cured  as 
quickly  as  possible  and  that  it  shall  not  lie  in  the  sun  or  dew 
to  become  bleached  and  stained.  To  do  this,  the  drying  of 
the  plants  must  be  hastened  by  the  circulation  of  air  through 
the  loose  hay.  The  leaves  give  up  moisture  to  the  air  rapidly 
and  draw  upon  the  supply  in  the  stem,  and  for  this  reason 
they  should  be  prevented  from  drying  up  and  f alUng  off. 

The  tedder  is  a  machine  arranged  to  pick  the  hay  from 
the  stubble  where  it  has  fallen  from  the  mower  and  has  been 
tramped  down  more  or 
less  by  the  team's  walk- 
ing over  it,  and  throw  it 
into  a  light  fluffy  layer 
through  which  the  air 
may  freely  circulate. 

The  size  of  the  ted- 
der is  designated  by  the 
number  of  forks  which 
stir  up  the  hay.  The  8-  and  10-fork  machines  are  the 
sizes  in  general  use.  Most  of  the  modern  machines  are 
made  almost  entirely  of  steel  and,  when  carefully  braced  to 
give  rigidity,  are  often  preferred  over  the  modern  wooden- 
frame  machines.  Various  combinations  of  gears,  sprockets, 
and  chains  are  used  to  drive  the  shaft  giving  motion  to  the 


Fig.  168.     A  steel   frame  hay  tedder. 


268  AGRICULTURAL  ENGINEERING 

forks.  One  does  not  seem  to  have  any  special  advantage  over 
the  other.  The  chain  is  the  more  flexible  connection  and 
costs  less  to  repair  than  a  broken  gear  when  an  accident 
occurs. 

MACHINES  FOR  FIELD  STACKING 

In  many  locahties  where  hay  is  one  of  the  principal  crops 
it  is  common  practice  to  stack  the  hay  in  the  field  until  a  time 
when  it  may  be  disposed  of  either  as  loose  hay  or  by  baling 
and  shipping.  The  factory-made  machines  used  for  field 
stacking  are  the  sweep  rake  and  the  stacker.  Each  of  these 
machines  may  be  secured  in  a  variety  of  styles. 

Sweep  Rakes.  The  sweep  rake  may  be  a  simple  affair 
drawn  over  the  stubble  on  skids  or  runners,  or  it  may  be 


Fig.    169.      A    haying   scene   showing   an    over-shot    stacker   and   sweep 
rakes  at  work. 

mounted  upon  wheels  with  elaborate  mechanism  for  balanc- 
ing and  raising  the  teeth.  With  some  of  these  rakes  the 
team  is  divided  and  one  horse  placed  at  either  side,  and  with 
others  the  team  is  hitched  to  a  tongue  in  the  rear.  The 
latter  type,  generally  called  the  three-wheeled  rake,  is  the 
more  expensive  and,  although  the  team  may  be  handled  to 
better  advantage,  is  difficult  to  guide. 


FARM  MACHINERY 


269 


Stackers.  Field  hay  stackers  are  divided  into  two  classes, 
the  plain  overshot  and  the  swinging  stacker.  The  first  has 
a  row  of  teeth,  corresponding  to  the  teeth  of  the  sweep  rake, 
on  the  end  of  long  arms  hinged  near  the  ground.  The  hay 
is  left  upon  these  teeth  by  backing  away  the  sweep  rake.  By 
means  of  a  rope  and  pulleys  the  teeth  are  raised  to  a  vertical 
position  and  the  load  of  hay  allowed  to  sHde  back  onto  the 
stack.  The  objections  of  this  type  of  stacker  are  that  the 
hay  must  always  be  raised  to  a  certain  height  regardless  of 
the  height  of  the  stack,  and  the  hay  is  always  dropped  in  the 
same  place  on  the  stack,  causing  it  to  settle  unevenly. 

The  swinging  stacker  has  a  row  of  teeth  on  arms  which 
may  be  raised  to  any  height  and  locked  in  place  by  a  brake 
engaging  the  rope;  then  the  hay  may  be  swung  over  the  stack 
and  dumped.  As  there  is  some  choice  as  to  where  the  load 
may  be  dumped,  this  style  of  stacker  offers  several  advan- 
tages.    It  may  also  be  used  in  loading  hay  onto  the  wagons. 

Homemade    Stacker.     Homemade   field    stacking    ma- 


Fig.  170.     A  homemade  field  stacking  outfit. 


270  AGRICULTURAL  ENGINEERING 

chines  are  quite  generally  and  successfully  used.  In  addition 
to  homemade  models  of  the  machine  described,  the  hayfork 
can  be  successfully  used  to  unload  hay  from  a  wagon  onto  a 
stack  by  the  use  of  some  sort  of  pole  and  pulley  arrangement, 
as  illustrated.  Where  a  hay  loader  is  available,  this  system 
of  stacking  offers  advantages  where  the  hay  must  be  hauled 
some  distance  before  stacking  and  where  it  is  desired  to  build 
an  especially  high  stack.  Apparatus  for  doing  field  work 
with  the  hayfork  may  be  purchased  by  those  who  do  not 
care  to  make  their  own  outfits. 

BARN  HAY  TOOLS 

Bam  Equipment.  The  equipment  for  putting  hay  into 
barns  consists  essentially  of  forks  or  slings  to  hold  the  hay 
while  being  moved  from  the  load,  hay  carriers  with  ropes  and 
pulleys,  and  a  track  on  which  the  carriers  run. 

Forks.  There  are  at  least  four  types  of  hayforks  in  use, 
each  of  which  is  adapted  to  particular  conditions.  The 
single  tine  has  spiu-s  at  the  lower  end  which  stand  out  at  right 
angles  to  hold  the  hay.  The  hay  is  released  by  tripping  the 
spurs,  allowing  them  to  turn  downward.  The  single-harpoon 
fork  is  adapted  to  handle  hay  which  hangs  together,  and  is 
used  where  it  is  not  desired  to  Hft  large  quantities  at  one  time. 

The  douhle-karpoon  fork  is  much  similar  to  the  single- 
harpoon  fork  except  that  two  tines  are  provided  instead  of 
one.     It  may  be  secured  in  lengths  from  25  to  35  inches. 

The  derrick  fork  is  used  quite  generally  for  handling  alfal- 
fa in  the  field,  but  is  adapted  to  a  variety  of  conditions.  It 
consists  of  a  frame  with  four  tines  at  right  angles.  It  is 
very  easy  to  insert  into  the  hay. 

The  grapple  fork  is  used  with  short  hay.  It  is  provided 
with  curved  tines  which  swing  toward  each  other  Hke  ice 
tongs,  firmly  gripping  the  hay.    The  tines  are  of  various 


FARM  MACHINERY 


271 


lengths  to  suit  conditions,  and  vary  from  four  to  eight  in 
number.     The  latter  may  be  used  in  handling  manure. 


Fig.  171.  Types  of  hay  forks  In  general  use:  1  is  the  simple  harpoon, 
2  the  double  harpoon,  3  the  derrick  fork,  and  4  a  four-tined  grapple 
fork. 

Slings.  Hay  slings  are  webs  made  up  of  ropes  and  stick 
which  are  placed  under  and  in  the  load  of  hay  in  such  a  way 
that  the  projecting  ends  may  be  brought  together  and  the 
hay  lying  in  the  sling  raised  at  one  time.  To  release  the 
hay,  a  spring  catch  is  provided  in  the  middle  which  allows 
the  sling  to  part  when  tripped. 

Hay  may  be  handled  very  quickly  with  sUngs;  as  much 
as  1000  pounds  may  be  handled  at  one  time  if  the  equipment 
is  strong  enough.    Thus  a  wagon- 
load  of  hay  may  be  removed  in 
three  or  even  two  sling  loads.     To 
obviate  the  trouble  of  placing  a        ^'^'  '''-    ^  ^^^  ^""^• 
sling  within  a  load,  a  fork  may  be  used  for  all  but  the  last 
which  may  be  taken  up  clean  by  a  sling  on  the  rack. 

Carriers.  Carriers  are  made  specially  for  forks,  for  slings, 
or  for  both.  The  latter  kind  is  known  as  a  combination  car- 
rier. The  size  varies  much  with  the  service.  Light  carriers 
are  used  with  forks,  and  heavy  carriers  with  double  trucks 
are  used  with  slings.  Carriers  which  may  be  used  in  either 
direction  from  the  stop  in  the  track  are  called  "two-way 


^^ 


272 


AGRICULTURAL  ENGINEERING 


carriers."  If  the  lower  part  of  the  carrier  can  be  turned 
about  without  removing  from  the  track,  the  carrier  is  said 
to  be  reversible. 

Tracks.  A  rather  large  variety 
of  steel  and  wooden  tracks  for  car- 
riers is  found  upon  the  market. 
The  wooden  track  is  usually  made 
of  material  four  inches  square. 
Steel  tracks  usually  have  a  T  or 
cross  form  of  cross-section.  Often 
the  latter  is  called  ''double- 
beaded"  tracks.  Various  forms 
of  switches  are  provided  to  convey 
hay  in  different  directions  from 
the  point  of  loading.  In  round  barns,  pulleys  are  provided 
for  carrying  the  rope  around  the  circular  track. 


Fig.   173. 


A   hay   carrier   on 
steel    traclc. 


QUESTIONS 

1.  What  is  the  standard  cutting  mechanism  for  mowers? 

2.  Describe  the  two  general  types  of  mowers. 

3.  Discuss  some  of  the  important  features  of  construction. 

4.  Why  is  a  gear  drive  preferable  to  a  chain  drive? 

5.  What  parts  of  a  mower  are  subject  to  excessive  wear? 

6.  Describe  the  two  principal  adjustments  of  a  mower. 

7.  Explain  the  points  to  consider  in  selecting  a  sulky  rake. 

8.  Explain  the  construction  and  use  of  the  hay  tedder. 

9.  Describe  two  types  of  side-delivery  rakes. 

10.  Describe  two  types  of  hay  loaders  and  give  the  merits  of  each. 

11.  State  the  difference  between  overshot  and  swinging  stackers. 

12.  How  may  homemade  outfits  be  arranged  for  field  stacking? 

13.  Describe  the  usual  bam  equipment  for  handling  hay. 

14.  Describe    the  construction   of   single-  and    double-harpoon, 
derrick,  and  grapple  forks. 

15.  What  advantages  do  slings  offer  for  unloading  hay? 

16.  Describe  the  different  hay  carriers. 

17.  What  kinds  of  hay  carrier  tracks  are  in  general  use? 


CHAPTER  XL 
MACfflNERY  FOR  CUTTING  ENSILAGE 

Types  of  Cutters.  There  are  two  general  types  of  ensilage 
cutters  upon  the  market,  and  a  third  which  is  used  to  a  limit- 
ed extent.  These  types  may  be  best  distinguished  by  the 
shape  of  the  knives  which  are  used.  The  first  is  the  radial 
knife  machine,  the  cutting  knives  of  which  are  attached  to  the 
side  of  a  large  balance  wheel.  These  knives  make  a  shear 
cut  with  the  cutting  plate  over  which  the  fodder  is  fed.  The 
second  type  may  be  designated  as  the  twisted  knife  machine. 
The  knives  of  this  type,  which  are  two  to  four  in  number, 
are  attached  to  spiders  on  the  main  shaft,  the  knives  being 
twisted  to  such  an  extent  that  a  cylinder  is  formed.    The 


Fig.   174.     An    ensilage  cutter    of    the    rarHal-knlfe    type    equipped  with 
blower  at  work. 

273 


274 


AGRICULTURAL  ENGINEERING 


fodder  is  fed  directly  into  the  cylinder.  The  third  type  of 
machine  has  a  large  number  of  narrow,  hook-shaped  knives 
arranged  spirally  around  the  main  shaft,  and  may  be  desig- 
nated as  the  spiral  knife  machine.  These  cut  as  well  as  split 
the  fodder  as  it  is  fed  directly  into  the  cyUnder. 

Considering  the  relative  merits  of  these  various  types  of 
machines,  the  radial  knife  certainly  has  the  advantage  in 
simplicity.  The  fan  blades  are  attached  directly  to  the 
main  cutting  wheel,  and  this  single  rotating  part  forms  the 
principal  portion  of  the  machine.  All  that  is  required  in  ad- 
dition is  the  feeding  mechanism.  The  knives  of  this  machine 
are  more  easily  sharpened,  as  they  are  at  least  straight  on 
the  flat  side.  As  the  knives  are  often  supported  their  entire 
length,  they  may  be  thinner,  requiring  less  grinding  in 
sharpening. 


"Fig.   175.      Cutting  heads  of    three  types  of    ensilage   cutters;  1    is 
radial  knife,  g   the  twisted  knife,  and  3  is  the  spiral  knife. 


The  twisted  knife  machine  is  capable  of  very  rigid  con- 
struction and  is  safe  against  an  explosion  from  overspeed. 
The  spiral  knives  may  be  sharpened  by  fihng  without  being 
removed  from  the  machine.       Most    machines     can    be 


FARM  MACHINERY  275 

furnished  with  interchangeable  shredder  knives  for  prepar- 
ing dry  fodder. 

Elevating  Mechanism.  The  pneumatic  elevator,  or 
blower,  offers  many  advantages  over  the  carrier  elevator. 
It  is  easily  adjusted  to  a  silo  of  any  height  and  is  less  likely 
than  others  to  cause  trouble.  It  requires  considerably  more 
power;  in  fact,  without  any  definite  information,  it  would 
seem  that  in  many  cases  the  blower  requires  at  least  one-half 
of  the  power  suppKed.  If  the  engine  is  large  and  there  is  a 
surplus  of  power,  the  convenience  of  the  blower  may  overbal- 
ance its  extravagance  in  consuming  power.  The  blower  is 
more  durable  than  the  long  chain  elevators.  It  must  be 
driven  above  a  certain  speed  or  sufficient  blast  will  not  be 
developed  to  elevate  the  silage.  The  blower  pipe  should 
always  be  set  nearly  vertical,  or  the  silage  will  settle  to  one 
side  of  the  pipe  and  not  be  elevated. 

Self -feed.  The  advantages  of  the  self -feed  are  so  great 
that  every  machine  should  be  provided  with  one.  This  self- 
feed  should  be  capable  of  having  its  speed  adjusted  to  furnish 
a  desired  length  of  cut.  The  length  of  cut  may  be  varied  in 
some  machines  from  34  inch  to  IJ^  inches.  Three-fourths 
of  an  inch  is  the  popular  length  of  cut  among  many  feeders. 
In  addition,  the  force  feed  should  have  a  safety  lever  for 
instantly  reversing  the  feed  rolls  and  carrier  in  order  to  pre- 
vent accidents. 

Mounting.  Ensilage  cutters  may  be  mounted  either  on 
skids  or  on  trucks.  The  trucks  add  much  to  their  conveni- 
ence, and  should  always  be  provided  for  the  larger  machines. 
In  selecting  the  machine  it  is  well  to  notice  if  the  truck  is  of 
good  substantial  construction.  There  has  been  a  tendency 
to  use  very  small  wheels,  often  of  cast-iron,  which  are  very 
hable  to  break. 


276 


AGRICULTURAL  ENGINEERING 


Construction.  Although  simplicity  is  desirable,  care 
should  be  used  in  selecting  a  cutter  to  see  that  it  is  provided 
with  a  good  strong  main  shaft,  supported  in  good,  long, 
babbitted  bearings,  and  mounted  in  a  substantial  frame. 
The  gearing  should  be  strong  enough  to  stand  the  variable 
load.  The  rolls  should  be  flexible  so  as  to  grip  the  fodder 
firmly.  The  self -feed  should  be  mounted  either  so  as  not  to 
require  folding  when  changing  location,  or  so  as  to  be  easily 
folded. 

Selection  of  an  Ensilage  Cutter.  The  selection  of  an 
ensilage  cutter  is  rather  a  difficult  task,  as  these  machines 

are  of  quite  recent  de- 
velopment and  accurate 
information  concerning 
the  relative  merits  of  the 
various  types  is  not  at 
hand.  In  deciding  upon 
the* size  or  capacity  of 
cutter,  several  factors 
are  involved.  On  the 
average  it  will  be  found 
that  a  cutter  will  require 
about  one  horsepower 
for  each  ton  of  capacity 
per  hour. 

The  gasoline  engine, 
either  portable  or  trac- 
tion, makes  a  good 
power  for  driving  the  ensilage  cutter.  Its  principal  ad- 
vantage lies  in  the  fact  that  it  does  not  require  constant 
attention.  As  many  farmers  have  gasoline  engines,  the 
cutter  must  often  be  selected  to  suit  the  engine.  The  power 
to  be  used  and  the  type  of  elevator  are  points  to  consider  in 


Fig.   176.    A  twisted-knife  ensilage   cutter 
equipped  witli   chain-carrier  elevator. 


FARM  MACHINERY  27T 

deciding  the  size.  It  is  quite  an  advantage  to  have  a  machine 
large  enough  to  take  the  bound  bundles  of  fodder  without 
cutting  the  bands.  The  smallest  cutter  equipped  with  a 
blower  which  will  do  this  will  require  at  least  a  12-horse- 
power  engine,  and  the  engine  must  be  liberally  rated  to  work 
successfully. 

The  common  practice  of  using  the  steam  traction  engines 
of  the  neighborhood  to  furnish  the  power  is  to  be  commended; 
first,  because  there  is  not  an  extra  outlay  of  money  for  ma- 
chinery; and,  secondly,  because  the  ordinary  traction  engine 
furnishes  abundant  power  for  even  the  largest  cutters. 
When  these  large  engines  are  used,  it  is  best  to  buy  a  large 
cutter  and  rush  the  silo  filling  through.  The  com  harvester 
may  be  operated  several  days  before  the  silo  filling  begins, 
in  order  that  the  fodder  will  be  available  as  fast  as  needed. 

QUESTIONS 

1.  Describe  three  types  of  knives  for  ensilage  cutters,  and  state 
some  of  the  advantages  for  each. 

2.  What  are  the  two  types  of  elevators  used  for  elevating  ensilage? 

3.  What  is  the  usual  length  of  cut  of  com  silage? 

4.  Upon  what  kind  of  truck  should  the  ensilage  cutter  be  mounted? 

5.  Describe  some  of  the  important  constructional  features  of  an 
ensilage    cutter. 

6.  What  are  some  of  the  important  factors  to  be  considered  in  mak- 
ing a  selection  of  an  ensilage  cutter? 


CHAPTER  XLI 
THRESHING  MACHINES 

Development.  It  is  a  big  step  of  progress  from  the  simple 
flail  to  the  modern  threshing  machine.  The  use  of  the  flail 
required  the  time  of  a  man  for  the  entire  winter  season  to 
thresh  even  a  very  moderate  crop  of  small  grain  which  he  had 
grown;  whereas  the  modern  machine  is  able  to  thresh  hun- 
dreds or  even  thousands  of  bushels  in  a  single  day,  deUvering 
it  cleaned  and  ready  for  market. 

The  Operation  of  Threshing.  The  modern  threshing  ma- 
chine performs  four  quite  distinct  operations.  The  first  is  the 
process  of  threshing  or  shelHng.  This  is  accomplished  when 
the  unthreshed  grain  passes  between  the  teeth  of  a  revolving 
cylinder  and  those  arranged  in  the  concave.  Second,  the 
machine  separates  the  straw  from  the  grain  and  chaff.  This 
operation  is  performed  by  the  grate,  the  beater,  the  check 
board,  and  the  straw  rack.  Third,  the  grain  is  separated 
from  the  chaff  and  dirt  by  screens  in  the  shoe  and  by  a  blast 
from  the  fan.  Fourth,  by  means  of  the  stacker  and  the  grain 
elevator  or  weigher,  the  straw  is  delivered  to  one  point  and 
the  grain  to  another. 

Cylinder.  The  cylinder  of  a  threshing  machine  is  built 
up  with  heavy  bars  of  steel  mounted  on  disks  or  spiders,  into 
which  the  teeth  are  fastened  by  thread  ends  and  nuts  or  by 
keys.  There  are  two  sizes  of  cylinders  in  use,  known  as  the 
small  and  the  big  cylinder.  The  big  cyUnder  usually  has 
about  20  bars.  The  speed  at  which  a  cylinder  revolves  will 
depend  upon  its  size,  but  varies  from  about  800  revolutions 
for  the  big  cyUnder  to  1100  revolutions  for  the  smaller  one. 

278 


FARM  MACHINERY 


279 


The  Concave.  The  concave  is  made  up  of  heavy  bars 
into  which  teeth  similar  to  cyUnder  teeth  are  fastened.  It  is 
located  below  the  cyUnder,  and  receives  its  name  from  its 
shape.  The  number  of  rows  of  teeth  may  vary  according 
to  the  kind  and  condition  of  threshing,  and  may  be  varied 
by  inserting  removing  bars.  The  concave  may  be  adjusted 
by  raising  or  lowering,  the  threshing  effect  being  greater 
when  the  teeth  are  high  and  entered  well  into  the  teeth  of 
the  cyHnder. 

The  Grate.  The  grate  consists  of  a  number  of  parallel 
bars  with  open  spaces  between,  placed  directly  beyond  the 


Fig.   177.     A  section  of  a  modern   threshing  machine. 


concave  teeth.  A  large  part  of  the  grain  and  chaff  is  allowed 
to  pass  through  this  grate  before  reaching  the  straw  rack 
beyond. 

The  beater  is  a  webbed  wheel  beyond  the  cylinder,  which 
beats  the  straw  into  a  stream  as  it  comes  from  the  cylinder 
and  enables  it  to  be  passed  quickly  over  the  straw  rack. 

The  Straw  Rack.  The  straw  rack  is  a  vibrating  rack 
which  allows  the  stream  of  straw  to  pass  over  it  but  which 
sifts  out  the  grain.  There  are  many  types  of  straw  racks 
in  use,  and  these  vary  in  their  construction  and  shaking 
motion. 


280  AGRICULTURAL  ENGINEERING 

The  Grain  Pan  or  Conveyor.  This  is  a  solid  removable 
bottom  which  extends  from  the  cylinder  back  to  the  shoe 
and  catches  all  of  the  grain  coming  from  the  grate  and 
through  the  straw  rack. 

The  Shoe.  The  shoe  is  the  frame  which  carries  the 
sieves.  In  it  the  grain  is  separated  from  the  chaff  as  the 
grain  and  chaff  pass  over  the  sieves  and  strike  a  blast  of  air 
from  the  fan.  The  sieves  and  the  blast  from  the  fan  are  sub- 
ject to  adjustment,  and  upon  their  skillful  manipulation 
depends  largely  the  efficiency  of  the  machine  in  cleaning  the 
grain. 

The  Self-Feeder  and  Band  Cutter.  The  self-feeder  is  an 
attachment  which  receives  bound  bundles  and  elevates  them 
to  the  throat  of  the  cylinder,  cuts  the  bands,  and  uniformly 
and  evenly  feeds  the  grain  into  the  cylinder. 

Straw  Stackers.  Formerly  the  straw  was  taken  care  of 
by  a  carrier,  which  consisted  of  a  frame  over  which  an  end- 
less web  was  drawn.  Later  this  tj^pe  of  carrier  was  made 
to  swing  in  different  directions  from  the  machine.  Most 
machines  of  the  present  day  are  equipped  with  wind  stack- 
ers, or  blowers.  These  stackers  have  a  fan  which  receives 
the  straw  from  the  straw  rack  and  blows  it  to  any  part  of 
the  stack  desired,  reducing  the  amount  of  labor  involved. 

The  Weigher.  The  majority  of  modern  machines  are 
equipped  with  a  weigher  to  measure  the  grain  as  it  is  delivered 
into  the  wagon  or  into  bags.  If  the  machine  is  simply  pro- 
vided with  an  attachment  to  elevate  the  grain  into  the  wagon 
box,  the  attachment  for  so  doing  is  called  the  grain  elevator. 

Size  of  Threshing  Machines.  There  are  usually  two 
dimensions  given  to  a  threshing  machine,  or  separator:  the 
first  is  the  length  of  the  cylinder,  and  the  second  is  the  inside 
width  of  the  machine,  where  the  various  separations  of  grain, 
straw,  and  chaff  are  brought  about.     The  sizes  vary  from 


FARM  MACHINERY  281 

18x22  inches  to  44x66  inches,  and  32x54  inches  to  36x58 
inches.  The  36x58-inch  separator  requires  from  25  to  40 
actual  horsepower  to  operate  it  successfully;  and  such  a 
machine  will  thresh  from  500  to  1000  bushels  of  wheat  in 
a  day,  or  about  twice  as  much  oats. 

Selection  of  a  Threshing  Machine.  The  choice  of  a 
threshing  machine  will  depend  largely  upon  the  amount  of 
grain  to  be  threshed  and  also  upon  the  method  followed  in 
threshing.  In  the  United  States,  it  is  customary  for  the 
threshing  to  be  done  by  experts  who  make  a  business  of  that 
kind  of  work.  There  are  some  locahties  where  the  individual 
farmer  owns  a  threshing  outfit,  in  which  case  the  smaller 
sizes  are  used.  Special  machines  are  provided  for  special 
conditions.  The  threshing  of  beans  and  peas  requires  a 
special  machine,  as  well  as  the  threshing  of  clover. 

QUESTIONS 

1.  Describe  the  four  distinct  operations  performed  by  the  modem 
threshing  machine. 

2.  Name  the  parts  that  perform  each  operation. 

3.  Describe  the  construction  of  the  cylinder. 

4.  Describe  the  concave  and  its  adjustment. 

5.  What  is  the  main  purpose  of  the  grate? 

6.  Where  is  the  straw  rack,  and  what  work  does  it  perform? 

7.  What  is  the  purpose  of  the  grain  pan? 

8.  What  function  is  performed  by  the  shoe? 

9.  Describe  the  construction  and  work  of  the  self-feeder. 

10.  What  is  the  work  of  the  weigher? 

11.  How  is  the  size  of  threshing  machines  designated? 

12.  What  are  some  of  the  important  considerations  involved  in  the 
selection  of  a  threshing  machine? 


CHAPTER  XLII 
FANNING  MILLS  AND  GRAIN  GRADERS 

The  Use  of  a  Fanning  Mill.  The  final  selection  of  small 
grain  seed  must  be  made  by  mechanical  methods.  The 
plant  breeder  may  well  afford  to  make  a  hand  selection  of 
seeds,  but  the  practical  grower  will  find  it  quite  impossible. 
There  are  from  700,000  to  1,000,000  wheat  berries,  about 
12,500,000  alfalfa  seeds,  and  as  many  as  120,000,000  timothy 
seeds  in  a  bushel.  A  bushel  of  com  contains  about  100,000 
kernels;  but  only  J^  to  ^  bushel  is  required  to  plant  one  acre, 
which  permits  seed  corn  to  be  graded  by  hand  more  readily 
than  other  grains.  However,  it  is  more  hkely  not  to  be  done 
at  all. 

Another  vital  requirement  of  good  seed  is  that  it  shall  not 
be  mixed  with  any  weed  seeds  which  will  foul  the  land  and 
reduce  the  value  of  the  crops.  Also,  in  order  that  the  modern 
seeding  and  planting  machinery  may  do  its  work  best,  the 
seed  should  be  free  from  trash  and  be  uniform  in  size  and 
weight.  The  first  step  to  be  taken  in  securing  a  uniform 
stand  Hes  in  cleaning  and  grading  the  seed. 

Often  two  or  more  grains  are  grown  together  or  become 
accidently  mixed,  and  the  fanning  mill  is  called  upon  to  sepa- 
rate out  the  different  kinds.  To  summarize,  the  functions 
of  the  fanning  mill  are: 

1.  To  clean  grain,  separating  out  trash  and  foul  seeds. 

2.  To  grade  grain,  securing  the  best  seed. 

3.  To  separate  different  kinds  of  grains. 

What  the  Fanning  Mill  Can  Do.  The  fanning  mill  or 
grain  grader  can  grade  clean,  or  separate  grains  only  when 

2S2 


FARM  MACHINERY 


V  283 


there  are  certain  physical  differences  between  the  grains  to 
be  separated.  It  is  reasonable  to  think  that  no  machine  can 
separate  two  grains  whose  difference  lies  wholly  in  the  name 
or  color.  The  modern  fanning  mill  is  arranged  to  utiUze 
several  of  the  physical  differences  which  may  exist  between 
grains.  These  differences  may  be,  (1)  difference  in  weight, 
(2)  difference  in  size,  (3)  difference  in  shape. 

In  addition,  the  roughness  of  the  hull  and  the  location  of 
the  heavy  part  of  the  seed  may  be  used  to  some  extent  in 
making  certain  selec- 
tions or  separations.  A 
separation  based  upon 
a  variance  in  weight  is 
made  by  the  use  of  a 
strong  current  of  air. 
Some  grain  graders  use 
this  method  almost 
entirely  at  the  present 
time,  and  formerly  all 
machines  depended 
principally  upon  *'fan-  ,        ,    , 

*^.         ^  11  J^'sr.    178.      A  section  of  a   fanning   mill   in 

ning       to    do    the    Sepa-    which    the    blast    does    not    strike    the    grain 

.  -  until  after  it  has  passed  through  the  sieves. 

ratmg,  hence  the  name 

fanning  mill.  No  doubt,  the  heavier  grains  are  the  most 
desirable  for  seed,  and  therefore  fanning  is  the  most  im- 
portant feature  of  the  modern  fanning  mill. 

Sieves,  screens  or  riddles  are  used  to  grade  the  grain 
according  to  size.  The  grain  first  passes  through  a  coarse 
screen,  which  takes  out  all  the  large  particles,  then  over  a 
finer  sieve,  or  a  combination  of  finer  sieves,  which  lets  the 
small  grains  and  weed  seeds  through  and  which  retains  the 
larger  seeds  in  one  or  more  grades. 


284  AGRICULTURAL  ENGINEERING 

Striking  examples  of  how  use  is  made  of  differences  in 
shape  are  found  in  the  devices  arranged  to  separate  wheat 
from  oats.  In  one  device  a  riddle  is  provided  with  cells 
having  a  reverse  turn.  The  short  wheat  grains  are  able  to 
pass  through  this  riddle,  but  the  long  oat  kernels  cannot. 
Another  device  consists  of  a  cloth  apron  over  the  grain  on 
the  sieve,  which  maintains  the  grain  in  a  thin  layer  and  pre- 
vents the  long  oat  kernels 
from  passing  through, 
because  the  cloth  pre- 
vents them  from  being 
upended.  The  wheat 
kernels,  being  shorter, 
pass  through  without 
difficulty. 

Certain    grains    like 
rye,    for    example,    are 
heavier   at  one   end   of 
Fig.  179.    Another  view  of  the  type  of  the   berry  than  at  the 

machine  shown  in   Fig.    178.  j.i_  i  'j?  xi 

other,  and  if  these  grams 
are  allowed  to  fall  a  certain  distance  they  are  quite  likely  to 
strike  upon  their  heavy  ends.  This  principle  is  made  use 
of  to  a  certain  extent  in  some  machines. 

Some  of  the  weed  seeds  which  are  found  in  grass  seed 
have  a  horny  or  burr-like  hull  which  enables  the  seeds  to 
adhere  readily  to  any  cloth  with  which  they  may  come  in 
contact.  This  characteristic  of  the  seeds  is  made  use  of,  in 
separating  them  out,  by  passing  the  seed  in  a  thin  stream 
over  a  felt  roll. 

In  general,  there  are  two  types  of  fanning  machines: 
First,  those  in  which  the  air  blast  is  directed  upon  the  grain 
as  it  passes  over  the  sieves;  and  second,  those  which  use  the 
air  blast  independent  of  the  sieves  and  riddles.    The  first  of 


FARM  MACHINERY 


285 


these  is  the  older  type.  It  has  a  rather  large  capacity  for 
the  amount  of  sieve  surface  provided,  and  when  properly 
handled  will  do  good  work.  The  latter  type,  however,  has 
the  greater  refinement  and  is  capable  of  more  careful  selec- 
tions. 

The  Selection  of  the  Fanning  Mill.  There  is  a  tendency 
among  certain  manufacturers  to  build  a  fanning  mill  of  such 
light  construction  as  to  be  neither  durable  nor  able  to  with- 
stand hard  service.  These  mills  soon  become  rickety  and  loose 
in  all  of  the  joints.  Therefore,  in  making  a  selection  of.a  fan- 
ning mill,  after  deter- 
mining definitely  that  it 
will  do  the  desired  work, 
it  should  be  carefully 
examined  to  see  whether 
or  not  the  frame  and 
the  body  of  the  machine 
are  made  of  good  mate- 
rial   and   well    put    to- 

Fig.  180.     A  section  of  a  fanning  mill   In     gCthcr.       Woodcn    kcyS 
which    the    blast     is     directed    below    and  j  •!  r 

through  the  sieves.  and    naiis  as  means  oi 

fastening  the  joints 
should  be  guarded  against.  The  shoe  which  carries  the  sieves 
should  be  well  made  to  withstand  the  constant  vibra- 
tion to  which  it  is  subjected,  and  conveniently  arranged 
for  the  adjustment  of  the  sieves.  It  is  best  that  the  length 
of  the  shaking  stroke  be  subject  to  adjustment,  as  small 
seeds  require  a  shorter  stroke  than  large  ones. 

Operation  and  Care.  The  air  blast  should  be  subject  to 
regulation,  either  by  changing  the  speed  of  the  fan  or  by 
varying  the  volume  of  air  supphed,  which  will  permit  it  to 
be  adapted  to  all  conditions.  Too  httle  attention  is  often 
given  to  the  construction  of  the  sieves.    The  frames  should 


286  AGRICULTURAL  ENGINEERING 

be  made  of  selected  material  and  well  put  together,  and  the 
wire  cloth  should  be  firm  and  not  easily  distorted.  Perfo- 
rated sieves  are  the  best  when  made  of  zinc.  They  are 
the  most  accurate,  as  the  perforations  are  quite  sure  to  be  of 
the  same  size.  Their  capacity,  however,  is  less,  and  they 
prevent  the  passage  of  a  blast  of  air  through  them. 

Sieves  should  be  well  cared  for.  A  punctured  or  sagged 
sieve  has  its  efficiency  very  much  reduced.  It  would  be  well 
to  provide  a  rack  for  storing  the  sieves  while  not  in  use. 
The  practice  of  pihng  them  one  upon  the  other  is  not  at  all 
to  be  commended. 

QUESTIONS 

1.  Why  is  the  fanning  mill  necessary  in  the  grading  of  small-grain 
seed? 

2.  What  are  the  three  functions  of  a  fanning  mill? 

3.  Upon  what  three  physical  differences  in  seed  does  separation 
depend? 

4.  What  devices  are  used  to  separate  by  differences  in  weight?  In 
size?    In  shape? 

5.  Describe  two  types  of  fanning  mills. 

6.  What  points  of  construction  should  be  observed  in  making  a 
selection  of  a  fanning  mill? 

7.  Describe  the  adjustments  of  the  blast  and  sieves  in  a  fanning 
mill. 

8.  Of  what  materials  are  the  sieves  made,  and  what  is  the  ad- 
vantage of  each? 

9.  How  should  the  sieves  be  cared  for? 


CHAPTER  XLIII 
PORTABLE  FARM  ELEVATORS 

The  Portable  Elevator.  One  of  the  most  recent  machines 
which  has  been  developed  to  relieve  the  farmer  of  some  of  the 
hardest  work  to  be  found  upon  the  farm  is  the  portable  ele- 
vator. Nothing  is  more  tiring  than  shoveUng  com  into  a 
crib  after  husking  all  day.  The  shoveling  of  wheat  and 
other  small  grains  into  the  granary  at  threshing  time  is  like- 
wise laborious.  The  portable  elevator  not  only  does  away 
with  the  hard  work  but  also  saves  time  and  reduces  the  help 
required,  both  of  which  are  to  be  obtained  only  at  a  premium 
during  a  rush  season.  A  good  elevator  will  do  the  work  of 
from  two  to  five  men. 

Besides  saving  labor,  time,  and  men,  the  portable  elevator 
makes  possible  the  construction  of  more  economical  cribs  and 
granaries.  These  can  be  built  much  higher,  thus  increasing 
their  capacity  without  increasing  the  cost  of  the  roof  or  the 
foundation.  With  elevators,  one  is  not  compelled  to  build 
cribs  or  granaries  on  low  foundations  when  wet  ground 
makes  it  undesirable. 

In  general,  the  portable  elevator  outfit  consists  of  a  dump- 
ing jack  to  lift  the  front  wheels  of  the  wagon  and  cause  the 
load  to  flow  to  the  rear ;  a  hopper  into  which  the  load  is  fed ;  an 
inclined  elevator  with  a  chain  carrier  of  flights  or  cups,  which 
carries  the  grain  to  the  highest  point  in  the  crib;  a  spout  or 
conveyor  to  distribute  the  grain  in  the  crib;  and  some  source 
of  power,  either  horse  power  or  engine. 

The  Lifting  Jack.  The  lifting  jack  is  made  in  two  styles, 
the  overhead  and  the  low-down.     The  former  has  a  yoke  or 

287 


288 


AGRICULTURAL  ENGINEERING 


frame  under  which  the  load  is  driven;  the  lifting  is  done  with 
either  ropes  or  chains  running  over  pulleys  above  and  back 
to  a  windlass  below.  The  overhead  type  is  the  simpler  of 
the  two,  but  is  a  little  inconvenient  to  move.  Ropes  are 
cheaper  than  chains,  but  are  less  durable. 

Nearly  all  of  the  various  devices  known  for  heavy  lifting 
are  used  with  fairly  good  success,  such  as  the  worm  gear,  the 
screw  and  nut,  the  hydraulic  lift,  the  rack  and  pinion,  and  the 
windlass.    The  worm  gear  with  windlass  is  one  of  the  most 


Fig.  181.     A  portable  farm   elevator  mounted  on  a  truck  and  equipped 
with  a   folding   hopper   and   a  low-down   dumping   jack. 

common  and  most  satisfactory.  As  a  usual  thing,  a  rough- 
cast worm  gear  is  not  a  lasting  part  of  a  machine,  and  if  port- 
able elevators  are  to  be  put  in  constant  use  no  doubt  greater 
refinement  would  be  necessary  at  this  point. 

The  pump  and  cylinder,  or  the  hydraulic  jacks,  are  built 
with  lifting  chains  extending  down  to  the  hubs  of  the  front 
wheels,  or  with  the  cylinder  placed  directly  under  the  front 
axle.  In  the  latter  type  the  piston  rod  has  a  yoke  at  the  top 
which  engages  the  axles  and  raises  the  entire  front  end  of  the 


FARM  MACHINERY  289 

wagon  as  the  oil,  which  is  always  the  fluid  used,  is  pumped 
into  the  cylinder  below  the  piston.  The  hydrauHc  jack  does 
not  raise  the  load  with  an  even  motion,  owing  to  the  intermit- 
tent action  of  the  pump. 

The  screw  and  nut  device  acting  upon  the  principle  of  the 
screw  jack  has  one  bad  feature,  and  that  is  the  lack  of  pro- 
tection of  the  screw  from  rust  and  dirt,  as  it  must  be  bright 
and  well  lubricated  at  all  times.  The  rack  and  pinion  is  a 
device  used  on  at  least  two  makes.  This  is  connected  to  the 
front  end  of  a  platform  at  each  comer,  and  the  wagon  is 
raised  on  the  platform.  This  method  obviates  the  difficulty 
of  dumping  wagons  of  long  and  short  wheel  bases.  All  jacks 
should  have  a  quick  return  motion  for  returning  the  wagon 
to  place. 

Wood  and  steel  are  used  in  the  construction  of  the  dump- 
ing jack.  Owing  to  the  fact  that  this  implement  is  usually 
exposed  more  or  less  to  the  weather,  during  its  season  of  use, 
at  least,  the  steel  construction  is  to  be  preferred.  If  the  jack 
is  to  be  moved  from  place  to  place  often  as  conditions  may 
require,  it  should  be  provided  with  a  truck,  which  most  manu- 
facturers will  furnish  at  a  slight  extra  cost. 

The  Hopper  and  Elevator.  The  hopper,  or  elevator 
extension,  is  made  so  as  to  be  raised  to  a  vertical  position  or 
swung  to  one  side  so  that  the  load  may  be  driven  into  the  jack 
or  dump.  In  the  first  type,  to  assist  in  lifting  the  hopper, 
springs  or  a  windlass  should  be,  and  usually  are,  provided. 
The  carrier  may  be  continuous  through  the  hopper  and  the 
elevator,  or  a  separate  carrier  or  web  may  be  provided  for 
each.  The  first  arrangement  permits  the  hopper  to  be  placed 
nearer  the  ground,  but  has  a  tendency  to  overload  the  chains 
of  the  carrier,  which,  in  many  cases,  have  too  much  to  do  for 
their  strength.  The  low  hopper  is  a  decided  advantage  in 
unloading  a  low-wheeled  wagon. 

10— 


290 


AGRICULTURAL  ENGINEERING 


Cups  and  Drag  Flights  are  used  for  conveying  the  grain 
up  the  carrier.  The  cups  seem  to  be  of  the  most  desirable 
construction  when  the  loaded  weight  is  carried  upon  rollers. 


Fig.    182.      A    portable    elevator    equipped   with    an    overhead    dumping 
jack,    swing   hopper,    and    conveyor    for    distributing    the    grain. 

In  the  first  place,  these  carriers  will  be  the  more  durable,  as 
the  scraping  action  of  the  flights  cannot  help  but  produce 
an  undue  amoimt  of  wear,  even  when  guides  are  provided 
to  keep  the  flights  free  from  the  bottom  of  the  elevator 
trough.  In  the  second  place,  the  cups  will  handle  any  kind 
of  grain. 

The  Derrick  and  the  Conveyor.  The  derrick  for  holding 
the  elevator  at  the  proper  angle  is  an  important  part  of  the 
machine.  It  should  be  so  arranged  that  it  may  be  erected 
quickly  after  being  folded  down,  and  should  be  provided  with 
a  powerful  windlass.  Cables  are  more  durable  than  ropes, 
especially  when  greased  occasionally  to  prevent  rust. 

If  the  elevator  is  to  be  moved  often,  the  elevator  proper, 
the  hopper  and  the  derrick,  should  be  mounted  on  a  truck. 
Some  of  these  trucks  are  very  cheaply  constructed;  yet,  unless 
the  elevator  is  to  be  moved  far  and  often,  an  expensive  truck 
is  not  needed. 


FARM  MACHINERY  291 

All  elevators  can  now  be  secured  with  conveyors  which 
may  be  installed  in  the  ridge  of  the  crib  or  granary  and  which 
permit  the  grain  to  be  discharged  through  a  spout  to  any 
point.  This  is  aocomphshed  usually  by  having  spouts  to  fit 
into  removable  sections  of  the  bottom,  or  by  shifting  the 
whole  conveyor  on  rollers.  If  the  elevator  is  to  have  a  perma- 
nent position  in  the  building,  the  conveyor  is  almost  essential. 
If  the  building  is  not  too  large,  a  better  arrangement  is  to  ele- 
vate the  grain  to  the  highest  point  possible,  often  to  a  cupola, 
and  distribute  it  through  a  spout  to  the  bins.  The  conveyor 
complicates  the  machine,  and  should  be  dispensed  with  if 
possible. 

If  a  two  or  three-horsepower  gasoline  engine  is  at  hand, 
it  may  conveniently  be  used  to  furnish  power  for  the  farm 
elevator;  otherwise,  a  one  or  two-horse  sweep-power  should 
be  purchased. 

Selection.  The  selection  of  a  portable  elevator  finally 
resolves  itself  into  the  choosing  of  a  machine  to  suit  the  kind 
or  kinds  of  grain  to  be  elevated,  and  a  careful  inspection  of 
the  construction  of  the  machines,  as  well  as  obtaining  from 
the  maker  a  guarantee  insuring  a  satisfactory  performance. 

QUESTIONS 

1.  Why  is  the  portable  elevator  an  important  machine  for  the  farm? 

2.  Describe  the  various  mechanisms  which  are  made  use  of  in  the 
lifting  jack. 

3.  Describe  some  important  features  of  the  construction  of  a 
portable  elevator. 

4.  Of  what  materials  are  portable  elevators  made? 

5.  What  are  the  relative  merits  of  cups  and  flights?  ; 

6.  Describe  the  construction  of  the  derrick.  j 

7.  How  are  conveyors  used  in  large  cribs? 

8.  What  features  should  be  given  careful  consideration  in  the 
selection  of  a  portable  elevator? 


CHAPTER  XLIV 
MANURE  SPREADERS 

The  Utility  of  the  Manure  Spreader.  The  manure 
spreader  will  not  only  enable  an  operator  to  spread  much 
more  manure  in  a  given  time  than  it  would  be  possible  to  do 
by  hand  with  a  fork,  but  better  work  is  performed.  A  ma- 
nure spreader  will  thoroughly  pulverize  the  manure  and 
spread  it  in  an  even  layer  over  the  field.  When  hand 
spreading  is  practiced,  the  manure  is  not  properly  pulverized 
but  is  spread  in  large  chunks  or  bunches,  which  ''fire  fang,'' 
thus  causing  a  large  part  of  the  fertility  to  be  lost. 

Construction.  A  manure  spreader  consists  essentially 
of  four  parts:  (1)  A  box  with  a  flexible,  movable  bottom, 
called  an  apron;  (2)  gearing,  or  a  mechanism  to  drive,  at  vari- 
ous speeds,  the  apron  conveying  the  manure  toward  the 
beater;  (3)  a  beater  or  toothed  drum,  which  receives  the 
manure  from  the  apron,  pulverizes  it  and  spreads  it  evenly 
behind  the  machine;  and  (4)  a  truck  to  carry  the  box  and  to 
enable  the  power  to  drive  the  machine. 


Pig.  183. 


A  modern  manure  spreader  at  work. 
292 


FARM  MACHINERY  *298 

Types.  There  are  two  general  types  of  manure  spreaders, 
classified  by  the  construction  of  the  aprons.  The  endless 
apron  passes  over  rollers  or  reels  at  each  end  of  the  box,  and 
is  arranged  to  be  driven  in  one  direction  only.  As  soon  as 
a  load  is  discharged,  the  apron  is  stopped  and  is  ready  to 
receive  another  load.  This  type  of  apron  is  more  likely 
to  become  fouled  by  manure  passing  through  the  upper  side 
and  lodging  in  the  inside  of  the  apron  below.  In  freezing 
weather  this  manure  on  the  inside  becomes  frozen,  and  is 
quite  likely  to  cause  breakage.  The  slats  are  placed  quite 
close,  however,  and  in  many  instances  these  troubles  are 
not  experienced  at  all.  One  maker  of  the  endless  apron 
spreader  has  the  slats  of  the  apron  hinged  so  that  while  on 
the  under  side  they  hang  vertically,  preventing  the  manure 
which  comes  through  the  upper  side  from  lodging  below. 
Again,  another  style  of  endless  apron  does  not  have  slats 
over  much  more  than  half  of  its  length,  and  in  this  way 
prevents  fouHng  by  leaving  the  under  side  open.  In  other 
instances  the  apron  proper  is  replaced  with  a  drag  chain 
which  drags  the  manure  over  the  tight  floor  of  the  box. 
Usually  this  type  of  apron,  or  conveyor,  to  be  more  correct, 
is  used  only  with  the  small-sized  machines,  as  the  amount 
of  power  required  to  drag  the  load  is  much  greater  than  to 
move  it  on  an  apron  supported  by  rollers. 

The  return  apron,  after  discharging  its  load,  is  brought 
back  into  position  again  by  a  reverse  motion.  The  return- 
apron  spreader  has  more  mechanism  than  the  endless  apron, 
on  account  of  this  return  motion.  The  front  end  board  is 
attached  to  the  apron  and  draws  the  load  well  into  the  beater 
at  the  finish. 

A  few  endless-apron  spreaders  have  a  front  end  board 
that  moves  with  the  load,  and  which,  after  the  load  has  been 
spread,  is  brought  forward  again  by  hand. 


294  ,  AGRICULTURAL  ENGINEERING 

Main  Drive.  The  main  drive  from  the  rear  wheels,  which 
furnish  the  power  to  the  beater,  is  an  important  part  of  the 
spreader.     Gears  and  chains  are  used  to  transmit  the  power. 

Chains  offer  an  advan- 
tage in  case  of  breakage, 
as  a  chain  can  be  easily 
and  cheaply  repaired. 
Breakage  is  more  likely 
to  occur  when  starting 
the  machine  than  at  any 
other  time.  To  prevent 
the  beater  from  throwing 

Fig.    184.     One  Type  of  driving  mechanism    OVCr  a  big  bunch  Of  ma- 
te the  beater.  ^^^^  ^^^^  ^^^  j^  motion, 

a  rear  end  board  is  provided,  which  is  raised  when  the  ma- 
chine is  started.  The  beater  may  also  be  moved  away  from  the 
manure  when  going  into  gear,  thus  overcoming  this  difficulty. 

The  Beater.  The  beater  for  pulverizing  the  manure  is 
made  up  of  bars  of  teeth  which  revolve  at  a  relatively  high 
speed  against  the  manure  fed  to  it  by  the  apron.  It 
should  be  constructed  of  durable  material;  wood  bars  are 
generally  used  to  hold  the  teeth,  but  beaters  made  entirely 
of  steel  are  used  on  a  few  machines.  The  size  does  not  seem 
to  be  so  important  so  long  as  the  teeth  are  given  the  proper 
speed  to  pulverize  the  manure  well.  The  height  of  the  beater 
in  reference  to  the  apron  is  important,  for  if  placed  too  low  it 
tends  to  drag  the  manure  over  without  pulverizing  it.  Beaters 
placed  high  are  quite  likely  to  cause  the  machine  to  be  of 
heavy  draft. 

The  teeth  of  some  beaters  are  placed  in  diagonal  rows 
around  the  beater,  which  tends  to  comb  the  manure  from  the 
center,  where  the  load  is  the  deepest,  toward  the  outside, 
giving  a  more  even  distribution. 


FARM  MACHINERY  295 

Several  devices  have  been  invented  to  spread  the  manure 
over  a  wider  swath  than  the  width  of  the  machine.  Under 
average  conditions  the  machine  requires  all  the  power  avail- 
able to  properly  pulverize  the  manure  needed  to  cover  the 
width  of  the  machine. 

Retarding  Rake.  To  prevent  the  manure  from  being 
thrown  over  in  large  bunches,  a  retarding  rake  is  provided  in 
front  of  the  beater.  In  some  machines  this  is  given  a  vibra- 
ting motion  which  tends  to  level  the  load. 

Apron  Drives.  There  are  at  least  two  mechanisms  in  use 
for  moving  the  apron  at  various  rates  of  speed  toward  the 
beater.  One  is  the  worm  drive,  in  connection  with  a  face 
wheel  and  pinion  to  give  variable  speeds.  This  device  gives 
a  uniform  motion  and  is  positive, 
preventing  the  apron  from  mov- 
ing too  fast,  as  when  the  spreader 
is  ascending  a  hill  and  the  load 
has  a  tendency  to  slide  back  into 
the  beater.  As  a  general  rule,  a 
worm  gear  when  used  in  this 
way  does  not  wear  well.    Some    „,      «.    ^  .... 

.      .       .  .  .  .  Fig.   185.     One   type  of  driving 

of  the  latest  machmeS  have  this  mechanism    to    the    apron. 

gear  inclosed  so  as  to  run  in  oil. 

The  ratchet  drive  is  simple  but  does  not  give  a  steady 
motion.  It  is  very  easy  to  obtain  a  wide  range  of  speed  with 
this  device.  The  ratchet  acts  only  in  one  direction,  and  in 
hilly  localities  the  apron  must  be  provided  with  a  brake  to 
prevent  it  from  feeding  too  fast  in  ascending  a  hill. 

The  return  motion  for  return-apron  spreaders  is  usually 
separate  from  the  feed,  and  safety  devices  are  provided  to 
prevent  the  possibility  of  having  both  motions  in  gear  at  the 
same  time. 


296  AGRICULTURAL  ENGINEERING 

The  Truck.  The  truck  of  the  manure  spreader  is  impor- 
tant, as  it  is  often  the  first  part  to  wear  out.  Steel  wheels 
are  quite  generally  used  now,  and  in  dry  climates  they  are 
preferable  to  wooden  ones.  It  is  also  important  that  the 
frame  of  the  truck  be  constructed  of  durable  material,  which 
should  be  well  braced  and  trussed.  Maple  is  to  be  preferred 
to  pine  for  the  frame. 

Capacity.  The  capacity,  or  size,  of  a  manure  spreader  is 
designated  in  bushels,  but  this  seems  to  be  an  arbitrary  unit 
at  the  present  time.  As  now  rated  the  capacity  would  be 
more  nearly  represented  by  cubic  feet. 

Low-down  Spreaders.  The  latest  development  in  ma- 
nure spreaders  is  the  low-down  spreader,  which  is  built  so  that 

the  top  of  the  bed  is  very 
low.  It  is  obvious  that 
this  type  of  construction 
reduces  the  labor  in  load- 
ing by  the  fork,  and  it 
is  also  more  convenient 
for  filling  from  a  litter 
carrier. 

Fig.  186.     A  low-down  spreader.  _,_  «  «  « 

Wagon  box  Spreader. 

The  wagon  box  spreader  is  a  machine  designed  to  be  placed 
on  the  rear  of  an  ordinary  farm  wagon  or  farm  truck. 
The  power  is  transmitted  by  sprockets  clamped  to  the  rear 
wheels.  This  machine  is  small,  light,  and  cheap;  it  fiu-nishes 
an  opportimity  to  use  the  truck  for  other  purposes.  The 
manure  spreader,  however,  is  a  machine  in  such  constant 
use  as  to  demand  a  truck  of  its  own. 

QUESTIONS 

1.  Why  is  machine  spreading  of  manure  to  be  preferred  to  hand 
spreading? 


FARM  MACHINERY  297 

2.  What  are  the  four  essential  parts  of  a  manure  spreader? 

3.  Describe  the  two  types  of  aprons  in  use,  and  what  are  the 
advantages  of  each? 

4.  What  is  a  drag  chain  conveyor? 

6.  What  is  the  use  of  a  front  end  board? 

6.  Describe  two  types  of  main  drive. 

7.  How  should  the  beater  be  constructed? 

8.  What  is  the  purpose  of  the  rear  end  board? 

9.  State  the  purpose  of  the  retarding  rake. 

10.  Describe  two  systems  of  apron  drives  and  give  the  merits  of 
each. 

11.  What  points  should  be  observed  in  selecting  a  truck? 

12.  How  is  the  size  or  capacity  of  a  manure  spreader  designated? 

13.  What  is  the  advantage  of  a  low-down  spreader? 

14.  Describe  the  wagon  box  spreader. 


'.m 


CHAPTER  XLV 
FEED  MILLS  AND  CORN  SHELLERS 


Feed  Mills.  The  work  of  the  feed  mill  is  the  reduction 
of  grain  to  meal.  In  some  machines  it  is  necessary  that  this 
process  be  accomplished  by  two  stages,  especially  if  ear  corn 
is  to  be  ground.  The  corn  first  passes  between  a  set  of  crush- 
ing rollers  and  then  through  the  main  grinding  mechanism  of 
grinding  plates  or  buhrstones.  Feed  mills  differ  most  in  the 
construction  of  the  grinding  plates  or  buhrstones. 

Grinding  Plates.  Buhrstones  are  used  where  a  very  fine 
meal,  such  as  is  required  for  table  purposes,  is  desired.  Most 
feed  mills  used  for  grinding  feed  for  live  stock  have  chilled- 
iron  grinding  plates.  These  are  hard,  they  wear  well,  and 
can  be  easily  replaced  at  a  small  expense  when  worn  out. 
These  grinding  plates  are  made  in  a  variety  of  shapes,  al- 
though the  flat  or  disk  shape  is  the  more  common.    They 

are  sometimes  made  cone  shaped. 
Roller  mills  are  used  to  some 
extent  for  grinding  feed  for  live 
stock.  These  rollers  are  generally 
made  smooth  and  depend  upon 
the  crushing  of  the  grain  to  reduce 
it.  The  roller  may  have  a  milled 
surface  and  revolve  against  the  fixed 
part  or  grinding  plate. 

The  Power  Mill.     Power  mills 

are  usually  arranged  to  be  driven 

by  a  belt  or  a  tumbhng  rod.    A 

A^eit-driven  feed  b^i^^ce  wheel  is  Considered  a  de- 


Fig.   187. 


FARM  MACHINERY 


299 


CO 


Fig.  188.  Grinding 
plates  of  chilled  cast 
iron. 


sirable  feature  of  a  power  mill,  as  it  enables  the  machine 

to  run  more  steadily.     When   two  kinds  of  grain   are  to 

be  ground  together,  a  divided  hopper  is  quite  an  advan 

tage.      Most    feed    mills    are   provided 

with  safety  devices    which   release   the 

grinding    plates    and    prevent    damage 

should  something  hard  be  fed  into  the 

mill,  or  with  quick  releases  which  will 

enable    the    operator   to    separate    the 

grinding  plates   quickly.      Such  mills  should  be  provided 

with  an  elevator  or  sacking  attachment  to  assist  in  caring 

for  the  ground  feed  as  it  is  prepared. 

Selection  of  a  Mill.  The  selection  consists  primarily  in 
securing  a  machine  constructed  with  bearings  which  will  run 
well  and  can  be  adjusted  easily,  and  with  grinding  plates 
which  can  be  easily  replaced  and  adjusted.  The  capacity 
of  feed  mills  and  the  amount  of  feed  which  the  mill  will  grind 
in  a  given  time  depend  upon  the  condition  of  the  grain  and 
the  fineness  of  grinding.  Furthermore,  the  capacity  of  the 
feed  mill  usually  becomes  less  and  less  from  the  time  the 
grinding  plates  are  new  until  they  are  replaced.  A  good  feed 
mill  should  grind  five  bushels  of  corn  or  two  to  three  bushels 

of  oats  for  each  horse- 
power used. 

CX)RN  SHELLERS 
There  are  two  general 
types  of  com  shellers  on 
the  market,  one  is  known 
as  the  spring  or  picker 
sheller  and  the  other  as 
the  cylinder  sheller. 

The  Spring  or  Picker 
Sheller.      The  spring  or 


Fig.  189.  A  small  two-hoe  picker- 
wheel  sheller  equipped  with  self-feeder, 
cob   carrier,    and   elevator. 


300 


AGRICULTURAL  ENGINEERING 


picker  sheller  is  the  one  in  more  general  use  and  is  adapted 
to  smaller  machines.  The  shelling  mechanism  consists  of  the 
picker  wheels,  the  bevel  runner,  and  the  rag  iron  mounted  on 
a  spring.  These  three  form  a  triangular  open  chute  through 
which  the  ears  of  corn  are  fed.  The  rag  iron  is  adjustable  to 
adapt  the  machine  to  large  or  small  ears.  On  large  machines 
a  self-feeder  is  provided,  which  arranges  the  ears  endwise 
and  feeds  them  into  the  sheller.  In  sheUing  large  cribs  of 
corn,  extension  feeders  are  provided  to  convey  the  corn  from 
the  crib  to  the  self-feeder. 

Cylinder  Shellers.    The  cylinder  sheller  consists  of  a 
beater  wheel  within  a  cylinder  made  up  of  parallel  steel  bars. 


Fig.    190.      A   section    of   a   picker-wheel    sheller. 

The  corn  is  fed  into  one  end  of  the  cyHnder,  and,  as  the  ears 
pass  along,  the  corn  is  shelled  by  being  crushed  against  the 
cylinder  by  the  revolving  beater  wheel.  Cylinder  shellers 
break  up  the  cobs  more  than  picker  shellers. 

Separating  Device.  All  power  shellers  should  be  pro- 
vided with  a  shoe  and  sieve,  and  a  fan  to  blow  out  the  chaff 
and  dust.  Sometimes  a  vibrating  rack  or  raddle  is  substi- 
tuted for  the  sieve.    After  being  cleaned,  the  corn  is  elevated 


FARM  MACHINERY 


301 


into  the  wagon  box,  and  the  cobs  are  conveyed  in  another 
direction  by  a  cob  carrier. 

Capacity.  The  size  of  a  picker  sheller  is  designated  by 
the  number  of  "holes,"  or  sets  of  sheUing  wheels,  and  these 
vary  from  the  one-hole  hand  machine  to  power  machines 
with  as  many  as  eight  holes.  The  average  size  is  the  four- 
hole  sheller,  which  will  usually  shell  from  100  to  200  bushels 
an  hour;  the  six-hole  will  shell  from  200  to  300  bushels  an 


Fig.   191.     A  section  of  a  cylinder  sheller. 

hour;  and  the  eight-hole,  500  to  600  bushels.  The  cylinder 
sheller  is  made  in  the  large  sizes  only,  some  having  a  capacity 
of  as  much  as  800  bushels  per  hour.  The  power  required  for 
operating  corn  shellers  varies  with  the  size.  The  four-hole 
power  shellers  with  all  attachments  will  usually  require  about 
eight  horsepower.  The  power  required  to  operate  cylinder 
shellers  will  vary  with  the  size,  style,  and  the  manufacturer's 
number. 

QUESTIONS 

1.  What  is  the  work  of  the  feed  mill? 

2.  Describe  the  various  types  of  grinding  plates  used  in  feed  mills. 


302  AGRICULTURAL  ENGINEERING 

3.  How  is  the  grain  reduced  by  means  of  rollers? 

4.  What  are  some  of  the  attachments  of  a  feed  grinder? 

5.  What  safety  device  is  usually  provided? 

6.  What  are  some  of  the  important  features  to  be  considered  in 
the  selection  of  a  feed  mill? 

7.  How  much  feed  may  be  ground  per  horsepower  per  hour? 

8.  What  are  the  two  distinct  types  of  corn  shellers  in  use? 

9.  Describe  the  shelling  mechanism  of  the  spring  or  picker  sheller. 

10.  Describe  the  cylinder  sheller. 

11.  Describe  some  of  the  attachments  provided  for  a  sheller. 

12.  What  is  the  capacity  of  various  sizes  of  corn  shellers? 

13.  How  much  power  is  required? 


CHAPTER  XLVI 
SPRAYING  MACHINERY 

Successful  fruit  growing  at  the  present  time  depends 
largely  upon  an  intelligent  and  skillful  fight  against  fungous 
diseases  and  injurious  insects.  Even  the  small  orchardist 
finds  that  he  cannot  afford  to  overlook  the  spraying  of  his 
trees  at  the  proper  time.  Field  spraying  has  been  introduced 
recently  to  exterminate  also  certain  noxious  weeds,  such 
as  mustard  in  grain  fields. 

Hand  Sprayers.  There  is  a  multitude  of  hand  sprayers 
or  syringes  upon  the  market,  but  it  is  not  the  purpose  to  take 
up  these.  The  use  of  these  appliances  is  Umited  to  the 
greenhouse  or  to  shrubbery.  The  bucket  sprayer  is  one  step 
in  advance,  and  may  be  used  quite  successfully  on  a  few  trees 
if  they  are  not  too  large.  Most  of  these  sprayers  throw  the 
spraying  solution  up  above  the  trees  in  such  a  way  that  the 
spray  falls  upon  the  foliage.  In  many  cases  this  is  undesir- 
able. The  spray  should  be  driven  into  the  foUage  in  such 
a  way  that  the  underside  of  the  leaves  and  the  inside  of  the 
flowers  will  be  reached  by  the  spray  solution.  A  Hberal  use 
of  brass  in  the  construction  of  the  small  sprayers  is  one  of  the 
features  which  indicates  quaUty. 

The  Barrel  Spray  Pump.  The  smallest  and  cheapest 
machine  for  spraying  small  orchards  is  the  barrel  pump. 
Where  a  few  trees  are  to  be  sprayed,  this  is  undoubtedly  the 
machine  that  should  be  selected. 

The  pump  may  be  mounted  on  either  the  end  or  the  side 
of  the  barrel.  If  located  on  the  side,  the  pump  will  more 
nearly  remove  all  of  the  solution  from  the  barrel,  as  the 

303 


304 


AGRICULTURAL  ENGINEERING 


suction  pipe  extends  to  the  lowest  point.  It  is  an  advan- 
tage to  have  the  pump  low,  as  the  handle  is  then  in  a  more 
convenient  position.  If  the  holes  cut  for  the  pump  and  the 
fiUing  funnels  are  not  too  large,  a  barrel  in  a  horizontal  posi- 
tion, with  two  heads,  is  more  rigid  and  less  likely  to  go  to 
pieces  when  empty  for  a  time. 

All  the  working  parts  that  come  in  contact  with  the 
spray  solution  should  be  brass,  as  it  is  the  only  metal  in  use 

which  will  resist  the  corrosive 
action  of  some  of  the  solutions 
in  common  use.  The  valves 
should  be  either  ball  or  poppet, 
with  removable  seats.  The  ball 
valve  seat  may  be  replaced  for 
a  nominal  sum,  making  this 
part  of  the  pump  as  good  as 
new.  Brass  poppet  or  disk 
valves  may  be  renewed  in  the 
same  manner,  or  they  may  be 
repaired  by  grinding.  Fine 
emery  with  oil  is  placed  be- 
tween the  valve  and  its  seat 
and  the  valve  turned  back  and 
forth  in  a  rotative  manner  until  the  surfaces  are  ground 
to  a  perfect  fit. 

The  plunger  type  of  cylinder  has  many  advantages.  It  is 
of  easy  access  for  repairs,  and  it  is  easy  to  determine  whether 
or  not  the  plunger  is  leaking.  The  packing  is  often  placed 
between  two  disks,  which  cause  the  packing  to  expand  as 
they  are  screwed  together  on  the  plunger  rod.  The  pump 
with  the  stuffing  box  and  the  inside  plunger  is  to  be  guarded 
against.    Of  course,  double-acting  pumps  must  have  stuff- 


Fig.  192.  A  good  type  of  barrel 
spray  pump  with  dash  agitator. 
Note  the  plunger  cylinder  and  the 
large   air   chamber. 


FARM  MACHINERY  305 

ing  boxes,  but  it  is  doubtful  if  the  double-acting  pump 
offers  much  advantage.  If  the  pump  cylinder  is  not  sub- 
merged, it  should  be  placed  near  the  surface  of  the  liquid 
in  the  barrel.  The  air  chamber  should  be  large,  as  it 
equalizes  the  pressure  and  makes  the  pump  easier  to 
operate. 

Every  barrel  pump  should  be  provided  with  an  agitator 
to  keep  the  heavy  spray  mixtures  stirred.  The  double-paddle 
type  is  undoubtedly  the  most  efficient  type  now  in  use,  but 
the  dash  agitator  is  in  more  common  use  and  is  quite  efficient. 

Field  Sprayers.  Field  sprayers  differ  largely  in  their  con- 
struction, as  they  are  designed  for  spraying  different  crops. 
First,  in  selecting  such  a  machine,  consideration  should  be 
given  to  the  truck  and  the  tank.  These  should  be  of  sub- 
stantial and  durable  construction.  The  gearing  driving  the 
pump  should  be  of  substantial  construction;  gears,  chains 
and  sprockeit.,  cranks,  cams,  and  eccentrics  are  used  in  this 
connection,  but  it  has  not  been  demonstrated  that  any  one 
particular  combination  has  any  special  advantages  over  any 
other.  The  size  of  the  pump  must  vary  with  the  number 
and  kind  of  nozzles  to  be  supplied.  Some  of  the  field  ma- 
chines used  for  spraying  mustard  and  other  weeds  are  of 
large  capacity,  supplying  as  many  as  twelve  nozzles  and 
covering  a  width  of  twenty  feet. 

Convenience  is  one  feature  of  great  importance  in  the 
field  sprayer.  The  machine  should  be  easy  to  fill  and  to 
control.  The  position  of  the  nozzles  should  be  susceptible 
of  any  adjustment  which  may  be  necessary.  The  pump  and 
driving  mechanism  should  be  of  ready  access  for  adjustment 
or  repairs. 

The  Power  Sprayer.  Where  there  is  a  considerable 
amount  of  orchard  spraying  to  be  done,  the  power  sprayer 
will  be  found  the  most  economical  and  efficient.    Man  power 


306 


AGRICULTURAL  ENGINEERING 


is  expensive,  and  it  is  well-nigh  impossible  to  maintain  suf- 
ficient high  pressure  by  hand  to  do  the  best  kind  of  spraying. 
Power.  Steam  engines  have  been  used  to  some  extent 
as  a  source  of  power  for  spray  pumps,  or  steam  has  been  used 
directly  in  direct-acting  steam  pumps.  The  great  weight 
of  the  steam  boiler  has  caused  its  replacement  by  the  gasoline 
engine  almost  entirely.     The  gasoline  engine  is  cheap  in  first 


Fig.  193.     A  power  sprayer. 


cost,  cheap  in  operation,  and  is  Hght,  which  make  it  especi- 
ally adapted  to  the  purpose. 

The  first  requisite  of  a  gasoHne  engine  for  a  spraying  out- 
fit is  reliabihty.  It  must  operate  under  adverse  conditions, 
and  there  should  be  sufficient  capacity  to  operate  continu- 
ously without  overheating. 

Pumps.  The  plunger  pump  with  outside  packing  of  the 
duplex  or  triplex  type  is  now  being  generally  used  in  the 


FARM  MACHINERY  307 

better  grades  of  spraying  outfits.  Since  these  are  more 
accessible  than  the  usual  double-acting  pump,  they  are  morr 
easily  packed.  The  triplex  pump  furnishes  a  more  even 
flow  of  liquid,  but  introduces  extra  parts  and  is  undoubtedly 
of  more  expensive  construction.  The  air  chamber  should 
be  designed  to  suit  the  kind  of  pump  used. 

The  Drive.  The  drive  from  the  engine  to  the  pump  is 
either  a  gear  or  a  combination  of  gear  and  belt.  If  a  gear 
is  used,  it  is  highly  essential  that  the  pump  and  the  engine 
be  mounted  upon  the  same  base,  thus  insuring  more  rigid 
construction. 

Agitator.  The  most  eflGicient  type  of  agitator  for  power 
sprayers  is  the  propeller  type.  The  small  screw  propellers 
in  the  tank  cause  the  hquid  to  circulate  rapidly  over  and 
over  in  the  tank,  carrying  the  heavy  particles  in  the  spray 
mixture  to  the  surface.  Dash  or  paddle  agitators  do  not 
produce  this  action. 

The  relief  valve  is  one  of  the  most  sensitive  parts  of  the 
modern  sprayer.  Its  purpose  is  to  regulate  the  pressure, 
allowing  the  surplus  liquid  pumped  to  return  to  the  tank. 
The  regulator  valve,  used  in  place  of  the  reUef  valve  and 
which  cuts  off  the  flow  to  the  .pump  after  a  certain  pressure 
has  been  reached,  is  a  commendable  device,  as  it  reheves  the 
engine  of  part  of  its  load  and  thus  reduces  the  wear  upon  it. 

Tank  and  Truck.  The  tank  and  truck  should  be  given 
careful  consideration.  In  general,  the  machine  which  may 
be  moved  about  the  most  easily  is  the  most  desirable.  For 
this  reason,  lightness  is  one  of  the  requisites  of  a  good  spraying 
rig.  As  the  sprayer  must  be  hauled  over  soft  ground,  high 
wheels  with  wide  tires  foi  the  truck  are  desirable.  The  con- 
struction should  permit  turning  in  very  hmited  space. 

Accessories.  The  hose,  extension  rods,  nozzles,  cut-offs, 
and  other  accessories  are  the  things  with  which  the  operator 


308 


AGRICULTURAL  ENGINEERING 


Fig. 


194.       The    Bordeaux    nozzle     and 
cluster  of  four  Vermorel  nozzles. 


must  work  directly,  and  often  efficient  work  will  depend  upon 
their  quality.  Cheap  hose  is  poor  economy.  The  extensions 
are  best  when  made  of  bamboo  with  a  brass  tube  on  the 
inside  to  carry  the  liquid.  Good  substantial  ferrules  should 
be  provided  at  the  ends  to  reUeve  the  thin  brass  tube  of  all 
strains  due  to  dragging  a  length  of  the  hose  about.  A  con- 
venient and  perfectly 
tight  shut-off  adds 
much  to  the  pleasure 
of  operation. 

There  are  two  gen- 
eral types  of  nozzles  in 
use:  the  Bordeaux 
nozzles,  in  which  a 
spray  is  produced  by  directing  the  jet  against  the  edge  of 
the  orifice;  and  the  Vermorel,  which  has  an  eddy  chamber 
directly  below  the  orifice.  In  the  latter,  the  liquid  is  given 
a  whirling  motion,  causing  it  to  be  driven  from  the  orifice 
in  a  cone-shaped  spray. 

The  Bordeaux  nozzle  produces  a  fan-shaped  spray,  which 
has  considerably  more  force  than  the  spray  from  the  Vermorel 
nozzle.  The  latter  is  generally  known  as  the  fine-spray 
nozzle;  by  making  the  eddy  chamber  and  the  orifice  large, 
the  spray  has  much  more  force  and  capacity. 

QUESTIONS 

1.  What  is  spraying  machinery  used  for? 

2.  State  some  of  the  important  construction  features  of  sprayers. 

3.  What  are  field  sprayers  used  for? 

4.  What  adjustment  should  be  provided  for  a  field  sprayer? 

5.  What  power  is  most  generally  used  for  power  sprayers? 

6.  Describe  the  different  types  of  spray  pumps  of  power  sprayers. 

7.  In  what  different  ways  is  the  pump  driven? 

8.  What  types  of  agitators  are  used  for  power  sprayers? 

9.  Describe  two  types  of  spray  nozzles. 


CHAPTER  XLVII 
THE    CARE    AND    REPAIR    OF    FARM    MACHINERY 

The  efficiency  of  modern  farm  operations  depends  pri- 
marily upon  the  successful  and  judicious  use  of  improved 
farm  machinery.  This  fact  is  generally  recognized.  No 
other  country  uses  as  much  machinery  as  the  United 
States.  The  Census  of  1910  showed  that  the  American 
farmer  was  annually  buying  149,318,544  dollars'  worth 
of  farm  machinery.  This  amount  was  equal  to  over  3.3  per 
cent  of  $4,499,319,838,  the  value  of  the  crops  raised.  It  is 
possible  at  this  time  to  make  only  a  rough  estimate  of  what 
percentage  of  the  farmers'  profits  3.3  per  cent  of  the  value 
of  crops  is..  Perhaps  20  to  30  per  cent  would  not  be  too  large. 
Any  feature  of  farm  management  which  absorbs  20  to  30  per 
cent  of  the  profits  is  well  entitled  to  earnest  consideration. 

Much  has  been  written  from  time  to  time  about  the  care- 
lessness of  the  American  farmer  in  caring  for  his  machinery. 
Various  estimates  have  been  made  of  the  life  and  deprecia- 
tion of  the  more  important  farm  machines.  Perhaps,  in 
many  cases,  these  estimates  have  been  too  low;  but  there 
is  little  doubt  in  the  mind  of  the  person  who  maizes  only  a 
casual  investigation,  that  average  life  of  most  farm  machines 
is  much  less  than  it  ought  to  be.  An  investigation  on  several 
farms  in  Minnesota*  indicates  the  average  depreciation  of 
farm  machines  to  be  7.3  per  cent  annually.  It  is  to  be  noted 
that  this  represents  the  most  favorable  conditions,  since  the 
farms  investigated  were  well  managed. 

The   care  or  management  of  farm  machinery  readily 

'''Bulletin  117,  Minn.  Agricultural  Experiment  Station. 

309 


310  AGRICULTURAL  ENOINEERINQ 

resolves  itself  into  three  heads :  repairing,  housing,  and  paint- 
ing. Of  these,  the  repair  item  is  perhaps  the  most  important. 
The  greater  part  of  the  average  farm  machine  is  not  subject 
to  wear,  and,  if  not  broken,  ought  to  last  indefinitely.  Con- 
sidering the  modern  gang  plow,  except  the  share,  moldboard, 
wheelboxes,  and  axles,  there  are  comparatively  few  parts  sub- 
j  ect  to  wear.  All  of  these  should  be  either  adj  ustable  or  renew- 
able at  a  small  expense.  The  main  parts  of  the  plow,  the 
parts  which  absorb  the  greater  part  of  the  cost  of  making, 
as  the  frame  and  the  beam,  ought  to  last  indefinitely.  Bail 
boxes  and  wheel  boxes  are  easily  and  cheaply  replaced,  and, 
when  renewed,  make  these  parts  of  the  plow  as  good  as  when 
it  left  the  factory. 

Repairing.  To  repair  farm  machinery  successfully  some 
system  must  be  used,  and  the  early  spring  is  the  time  of 
year  to  give  thought  to  this.  No  doubt  many  a  machine 
is  taken  from  storage  in  the  spring,  or  whenever  the  machine 
is  needed,  and  the  owner  finds  that  he  has  forgotten  to 
order  certain  repairs,  which,  he  remembers,  were  needed  at 
the  close  of  the  previous  season.  When  he  proceeds  to  order 
these  repairs  from  his  agent,  he  finds  that  others  have  done 
hkewise;  and  the  agent,  the  jobber,  and  the  manufacturer 
are  rushed  with  orders.  There  are  always  delays  and  short- 
ages, which  often  result  in  the  purchase  of  new  machines, 
as  those  familiar  with  the  farm  industry  are  aware.  If  the 
necessary  parts  had  been  ordered  months  before,  they  would 
have  been  secured  without  fail,  and  they  could  have  been 
put  in  place  on  the  machine  and  the  machine  adjusted  and 
made  ready  for  work.  Repairs  for  the  older  machines  are 
not  carried  in  stock  except  at  the  factory,  and  for  this  reason 
plenty  of  time  must  be  allowed  for  filUng  orders.  Again,  it 
would  be  a  decided  advantage  to  repair  the  machinery  at  the 
time  of  the  year  when  work  is  less  pressing.    On  most  farms 


FARM  MACHINERY  311 

some  of  the  winter  months  offer  a  good  opportunity  to  do 
miscellaneous  work  of  this  character. 

System  of  Repairs.  A  definite  sytem  has  proven  to  be 
very  useful  in  keeping  farm  machinery  in  repair.  As  each 
machine  finishes  its  work  for  the  season  and  is  placed  in  the 
implement  house,  a  tag  with  a  string  is  taken  from  a  conveni- 
ent place  and  a  record  is  made  of  the  repairs  that  the  machine 
needs  for  the  next  year.  It  is  much  easier  to  make  this  record 
at  that  time  than  later,  as  everything  is  fresh  in  mind.  An 
inspection  of  this  tag  at  any  time  will  show  just  what  the 
machine  needs  in  the  way  of  repairs.  Before  the  busy  sea- 
son all  the  machinery  should  be  gone  over  systematically, 
and  the  needed  parts  sent  for  or  repaired  in  the  home  shop. 

More  emphasis  should  be  placed  upon  the  matter  of 
systematic  repairing  than  upon  any  other  phase  of  the  care 
of  fartn  machinery. 

Housing.  II  may  be  demonstrated  that  rust  is  more 
destructive  than  wear.  A  striking  example  of  this  is  found 
in  the  harvester.  Its  average  life  extends  over  a  certain  term 
of  years,  largely  independent  of  whether  it  harvests  40  or 
200  acres  of  grain  each  year.  Again,  we  find  in  machine 
shops  and  factories  machinery  which  has  lasted  as  long  as 
the  harvester  and  which,  instead  of  being  in  operation  a  few 
days  in  a  year,  is  in  operation  ten  hours  or  more  day  in  and 
day  out  without  rest. 

Wooden  parts  are  affected  more  by  exposure  to  the  weather 
than  metal  parts,  but  both  are  materially  injured.  Not 
only  is  the  life  of  machinery  shortened,  but  its  efficiency,  the 
quality  of  its  work,  is  lowered  by  not  being  carefully  protected 
from  the  weather.  The  average  farm  requires  about  $1000 
worth  of  machinery.  This  may  be  nicely  housed  in  a  build- 
ing costing  $200,  an  investment  that  will  pay  good  divi- 
dends in  protecting  and  prolonging  the  life  of  the  machinery. 


312  AGRICULTURAL  ENGINEERING 

The  construction  of  the  implement  house  will  be  discussed 
in  a  later  chapter. 

Painting.  Painting  is  simply  providing  each  implement 
with  a  house  of  its  own.  Wooden  parts  deteriorate  rapidly 
when  moisture  is  allowed  to  penetrate  the  surface.  Wood 
decays  and  warps,  rendering  it  weak  and  useless  for  the  pur- 
pose for  which  it  is  used.  Unprotected  iron  or  steel  when 
exposed  to  the  weather  unites  with  oxygen  of  the  air,  or 
rusts,  gradually  giving  up  its  strength.  Steel  bridges  decay 
in  this  manner  so  rapidly  that  they  must  be  replaced  after 
a  term  of  years.  To  protect  these  metals,  their  surfaces  are 
coated  with  paint  to  keep  out  the  moisture  and  air.  Rail- 
road companies  and  large  corporations  find  it  profitable  to 
keep  their  steel  bridges  and  stuctural  work  well  painted. 

Perhaps  there  is  no  better  paint  for  implements,  not  tak- 
ing into  account  a  personal  dislike  which  some  have  for  the 
color,  than  red  lead  and  linseed  oil.  This  paint  will  adhere 
well  to  clean  surfaces  of  wood  and  iron,  and  is  affected  about 
as  Httle  by  the  weather  as  anything  that  can  be  used. 

Besides  prolonging  the  life  of  the  machines  themselves, 
a  machine  dressed  in  a  good  coat  of  paint  commands  more 
respect  and  is  looked  upon  as  being  a  better  machine.  The 
author  can  recall  specific  instances  where  a  coat  of  paint 
has  increased  the  seUing  price  of  machinery  fifty  per  cent 
or  more. 

QUESTIONS 

1.  How  much  does  the  American  farmer  spend  annually  for  farm 
machinery? 

2.  What  percentage  is  this  of  his  gross  and  of  his  net  income? 

3.  What  is  the  average  depreciation  of  farm  machinery? 

4.  Explain  why  the  repair  of  farm  machinery  is  so  important. 

5.  Describe  a  system  of  keeping  all  farm  machinery  in  good  repair. 

6.  Why  is  the  housing  of  farm  machinery  so  important? 

7.  Give  several  reasons  why  machinery  should  be  kept  painted. 


PART  SIX— FARM  MOTORS 


CHAPTER  XLVIII 
ELEMENTARY  PRINCIPLES  AND  DEFINITIONS 

Farm  Motors.  Farm  motors  as  discussed  in  this  text 
include  machines  which  furnish  power  for  operating  farm 
machinery.  In  the  broadest  sense,  the  term  farm  machinery 
includes  farm  motors.  Owing  to  a  lack  of  space  it  will  be 
possible  to  consider  only  such  motors  as  are  in  general  use  for 
agricultural  purposes. 

Energy.  Energy  may  be  defined  as  the  power  of  pro- 
ducing a  change  of  any  kind.  It  is  the  function  of  a  motor  to 
utilize  and  transform  energy  in  such  a  way  that  it  may  be 
used  in  operating  machinery.  There  are  two  general  forms 
of  energy:  (1)  potential  or  stored  energy,  Hke  that  con- 
tained in  unbumed  coal;  and  (2)  kinetic,  or  energy  of 
motion,  an  example  of  which  is  the  energy  of  the  wind. 

Sources  of  Energy.  The  sources  of  energy  which  are 
made  use  of  by  farm  motors  are  feed,  fuel,  and  the  wind. 
The  first  two  of  these  represent  potential  energy  and  the 
last  kinetic. 

The  Most  Important  Farm  Motors.  The  motors  which 
are  used  generally  for  operating  farm  machinery  are  the  horse, 
the  windmill,  the  gas,  gasoline,  or  oil  engine,  and  the  steam 
engine.  Other  types  of  motors,  such  as  the  water  wheel  and 
the  electric  motor,  are  used  to  a  hmited  extent  for  agricultural 
purposes.  All  of  these  motors,  with  the  exception  of  the 
electric  motor,  are  priine  movers;  that  is,  they  take  the  energy 

313 


314  AGRICULTURAL  ENGINEERING 

in  the  form  of  food,  fuel,  or  wind  and  convert  it  into  mechan- 
ical energy,  which  may  be  used  in  driving  machinery.  The 
electric  motor  is  driven  by  electric  energy,  furnished  either 
by  an  electric  generator,  driven  by  a  prime  mover,  or  by 
chemical  action,  hke  the  electricity  from  an  electric  battery. 
Forces.  A  force  is  that  which  produces,  or  tends  to  pro- 
duce or  destroy,  motion.  A  force  has  two 
characteristics,  magnitude  or  size,  and  direc- 
tion. The  unit  by  which  the  magnitude 
of  a  force  is  designated  or  measured  is  the 
pound.  The  pound  is  the  action  of  the  force . 
of  gravity  on  a  definite  mass.  When  two  or 
more  forces  act  at  a  point  their  combined 
action  is  equal  to  the  action  of  one  force, 
called  the  resultant.  In  a  reverse  manner  a 
force  may  be  divided  into  components,  which  act  in  different 
directions  from  that  of  the  force. 

Work.  When  a  force  acts  through  a  certain  distance,  or 
when  motion  is  produced  by  the  action  of  a  force,  work  is 
done.  Work  is  often  defined  as  the  product  of  force  times 
distance. 

The  Unit  of  Work.  The  unit  of  work  is  the  foot  pound, 
or  the  equivalent  of  the  force  of  one  pound  acting  through  a 
distance  of  one  foot.  Thus,  for  example,  the  work  done  in 
raising  a  weight  of  one  pound  five  feet  or  five  pounds  one  foot 
would  be  five  foot  pounds. 

Power.  Power  is  the  rate  of  work.  In  determining  the 
rate  of  work  time  is  a  factor.  Thus  the  measurement  of 
power  consists  in  determining  the  number  of  foot  pounds  of 
work  done  in  a  certain  time. 

The  Unit  of  Power.  The  unit  of  power  in  common  use  is 
the  horsepower.  It  was  established  arbitrarily,  and  is 
equal  to  33,000  foot  pounds  of  work  per  minute.     Thus  if  the 


FARM  MOTORS  315 

product  of  the  force  in  pounds  by  the  distance  in  feet  traveled 

in  one  minute  be  33,000,  one  horsepower  of  work  would  be 

done.     In  measuring  horsepower  it  is  customary  to  determine 

the  number  of  foot  pounds  of  work  done  in  a  minute  and 

divide  by  33,000.     For  example,  suppose  a  horse  walks  165 

feet  per  minute  and  exerts  a  pull  of  200  pounds  on  his  traces; 

then  the  horsepower  developed  will  be: 

200X165 

=  1  horsepower 

33,000 

QUESTIONS 

1.  What   is   energy? 

2.  What  is  the  function  of  a  motor? 

3.  Explain  the  two  general  forms  of  energy. 

4.  What  are  the  principal  sources  of  energy? 

5.  Name  the  most  important  farm  motors. 

6.  What  is  a  prime  mover? 

7.  What  is  a  force? 

8.  How  may  a  force  be  illustrated? 

9.  Illustrate  resultant  and  component  forces. 

10.  Define  work. 

11.  In  what  units  is  work  measured? 

12.  Define  power. 

13.  What  is  the  conmion  imit  of  power  and  what  is  its  equivalent? 


CHAPTER  XLIX 
MEASUREMENT  OF  POWER 

The  Necessity  of  Measuring  Power.  The  cost  of  power 
is  one  of  the  largest  items  in  the  cost  of  performing  farm 
operations.  In  general,  operating  costs  on  modern  farms  can 
be  readily  divided  into  the  cost  of  labor,  of  power,  and  of 
machinery.  It  is  desirable  to  keep  each  of  these  items  as  low 
as  possible,  as  long  as  it  will  make  the  total  cost  lower.  Of 
these  three  items  the  labor  and  power  costs  are  by  far  the 
largest,  and  it  is  desirable  that  every  farmer  be  able  to  ana- 
lyze them  carefully.  In  order  to  determine  the  cost  of  power 
accurately,  it  is  necessary  to  know  how  the  power  furnished 
by  different  motors  may  be  measured  and  compared. 

Quantities  Which  Must  Be  Determined.  Power  has 
already  been  defined  as  the  rate  of  work.  Then  in  measuring 
power  it  is  necessary  to  determine  the  amount  of  work  done 
in  a  certain  length  of  time.  Thus  the  problem  is  simply  a 
matter  of  determining  these  three  quantities,  the  force,  the 
distance,  and  the  time. 

Measuring  the  Power  of  an  Engine.  The  power  of  an 
engine  is  commonly  measured  by  applying  a  so-called  Prony 
brake  to  the  pulley  or  fly  wheel.  This  brake  increases  the 
friction  until  the  entire  power  of  the  engine  is  required  to 
rotate  the  fly  wheel  or  pulley  within  the  brake  when  held 
stationary.  By  allowing  the  arm  of  this  brake  to  rest  upon  a 
scale,  the  force  required  to  move  the  pulley  or  wheel  within 
the  brake  is  found. 

The  distance  traveled  in  one  minute  by  this  force  as 
measured  by  the  scale  is  equal  to  the  circumference  of  a  circle 

316 


FARM  MOTORS 


317 


whose  diameter  is  twice  the  length  of  the  brake  arm,  times 
the  number  of  revolutions  made  by  the  engine  in  a  minute. 
Thus  it  is  seen  that  it  is  not  difficult  to  make  a  simple  test  of 


'5rato 


Fig.    197.      The   Prony  brake  as  applied  to  the   pulley   of  an  engine   to 
measure   the  power    (From   Farm    Machinery    and    Farm   Motors). 

an  engine.  All  that  is  needed  is  a  brake,  a  scale  for  measur- 
ing the  force,  a  speed  indicator  or  revolution  counter,  and  a 
watch  to  determine  the  revolutions  per  minute. 

The  distance  per  minute  multipUed  by  the  force  as  indi- 
cated by  the  scale  gives  the  number  of  foot  pounds  of  work 
done  in  one  minute,  and  this  divided  by  33,000  gives  the 
horsepower.    Stated  in  the  form  of  a  formula  it  is  as  follows : 


H.P.= 


net  load  on  scale  X  2  X  length  of  brake  arm 
(in  ft.)  X  3.1416  X  rev.  per  min. 


33,000 


Dynamometers.  A  dynamometer  is  an  instrument  used 
in  measuring  power.  The  Prony 
brake  referred  to  above  may  be 
called  an  absorption  dynamome- 
ter, in  that  in  the  measurement 
the  power  is  used  up  by  friction. 
A  dynamometer  which   measures 


%^*: 


Fig      198.        A      direct-reaiing 
traction  dynamometer. 


318 


AGRICULTURAL  ENGINEERING 


the  power  while  still  allowing  it  to  be  used  in  driving  the 
machine  is  called  a  transmission  dynamometer.  Instru- 
ments used  for  measuring  the  draft  of  implements  in  the 
field  are  called  traction  dynamometers.  Those  which  simply 
indicate  by  a  needle  and  dial  the  draft  or  force  required 


Fig.    199.     A  recording  dynamometer  as  designed   by  the  Agri- 
cultural Engineering  Section  of  the  Iowa  Agr.  Exp.  Station. 

to  move  the  implement  are  called  indicating  or  direct-reading 
dynamometers.  One  provided  with  rolls  of  paper  operated 
by  clock  mechanism  or  by  a  wheel  in  contact  with  the  ground, 
over  which  a  pencil  moves  and  records  the  draft,  is  said  to  be  a 
recording  dynamometer.  There  are  also  a  few  kinds  on  the 
market  which  average  the  draft  over  a  measured  run. 


QUESTIONS 

1.  Why  is  an  understanding  of  the  measurement  of  power 
portant? 


FARM  MOTORS  319 

2.  What  quantities  must  be  determined  in  the  measurement  oi 
wwer? 

3.  Describe  in  detail  how  the  power  of  an  engine  is  measured. 

4.  Explain  the  formula  for  calculating  horsepower. 

5.  What  is  a  dynamometer? 

6.  Describe  an  indicating  dynamometer. 

7.  How  is  a  dynamometer  made  a  recording  instrument? 


CHAPTER  L 
TRANSMISSION  OF  POWER 

Not  all  machines  can  be  so  placed  as  to  be  driven  directly 
by  the  motor,  and  so  there  must  be  some  means  of  transmit- 
ting the  power  to  the  machine. 

Belting.  One  of  the  most  common  forms  of  transmitting 
power  from  one  rotating  shaft  to  another  is  by  belting.  In 
this  case  the  power  is  transmitted  by  the  friction  between  the 
belt  and  the  pulley,  producing  rotation.  While  transmit- 
ting power  a  belt  is  under  greater  tension  on  one  side,  the 
"tight  side,''  than  on  the  other,  or  "slack  side."  The  actual 
force  transmitted  is  equal  to  the  difference  in  the  tension  of 
the  "tight  side"  and  the  "slack  side."  The  power  trans- 
mitted depends  also  upon  the  speed  of  the  belt  or  the  distance 
the  force  travels  in  a  given  time. 

Horsepower  of  Belting.  In  installing  a  power  plant  of 
any  sort  in  which  belting  is  used,  it  is  necessary  to  determine 
the  size  of  belts  which  will  transmit  the  desired  amount  of 
power.  A  formula  quite  generally  used  in  estimating  the 
horsepower  of  leather  belts  is  as  follows: 

V  X  w 
H.  P.  =  

1000 
where  H.  P.  equals  the  horsepower;  V  the  velocity  of  the   belt 
in  feet  per  minute;  and  W  the  width  of  the  belt  in  inches. 

If  the  speed  of  the  driving  pulley,  which  furnishes  power, 
and  its  diameter  be  known,  V  may  be  easily  obtained  by 
multiplying  the  circumference  of  the  pulley  in  feet  by  the 
revolutions  per  minute.    A  belt  should  seldom  travel  more 

320 


FARM  MOTORS 


321 


than  4000  feet  per  minute,  and  2000  feet  is  a  more  common 
velocity. 

Leather  Belting.  Leather  is  the  standard  material  for 
belting  and  is  considered  the  most  durable,  when  protected 
from  heat  and  moisture.  A  good  leather  belt  should  last 
from  ten  to  fifteen  years  when  used  continuously.  It  is 
customary  to  run  the  belt  with  the  grain  or  smooth  side  next 
to  the  pulley,  as  the  strength  of  the  leather  is  largely  centered 
in  this  side  of  the  belt;  if  run  with  the  smooth  side  out  it  is 
quite  hkely  to  become  cracked. 

In  order  that  leather  belts  should  render  good  service  they 
should  be  properly  cared  for. 
As  a  belt  bends,  the  fibers  of 
the  leather  slip  over  one  an- 
other, and  for  this  reason  belts 
should  be  oiled  or  lubricated. 
Neatsfoot  oil  is  the  standard 
oil  for  this  purpose.  There  are 
many  good  belt  dressings  on 
the  market,  but  there  are  oth- 
ers which  are  decidedly  inju- 
rious. A  leather  belt  works  best 
when  pliable  enough  to  adhere  closely  to  the  pulley,  and 
rosin  and  other  such  materials  are  to  be  avoided. 

Rubber  Belting.  Rubber  belting  is  made  of  canvas 
thoroughly  covered  with  rubber.  It  is  made  in  thicknesses 
of  two-ply  and  up,  three-  and  four-ply  being  common  thick- 
nesses. A  rubber  belt  operates  quite  satisfactorily  imder 
wet  conditions. 

Canvas  Belting.  Canvas  belting  consists  of  several  thick- 
nesses of  canvas,  four-  and  five-ply  belts  being  the  most  com- 
mon. The  canvas  is  thoroughly  stitched  together  and  then 
filled  with  oil  to  keep  out  the  moisture,  and  finally  painted. 


Fiff.  200.     Sample  of  canvas,  rub- 
ber, and  leather  belting. 


322 


AGRICULTURAL  ENGINEERING 


The  canvas  belt  is  the  most  economical  in  cost  and  is  very- 
strong.  It  lengthens  and  contracts,  however,  with  moisture 
changes;  hence  is  not  suitable  for  pulleys  at  fixed  distances. 
Canvas  belting  is  used  largely  in  connection  with  agricultural 
machinery,  being  almost  universally  used  in  driving  threshers 
and  similar  machines. 

Lacing  of  Belts.  The  common  practice  of  splicing  belts 
is  by  means  of  a  rawhide  thong,  often  called  a  belt  lace. 
Holes  are  punched  at  about  five-eighths 
inch  from  each  end  of  the  belt  and  oppo- 
site each  other.  In  order  to  give  greater 
strength,  two  rows  of  holes  are  often 
punched,  the  second  row  being  set  back 
farther  from  the  end  of  the  belt.  The 
accompanying  illustration  shows  a 
A  good  good  style  of  lacing.  The  lace  on  the 
side  next  the  pulley  should  not  cross 
diagonally  from  one  hole  to  another,  but  should  extend 
directly  across  the  spHce. 

Where  the  belt  is  to  pass  around  an  idler  and  thus  be  com- 
pelled to  bend  in  both  directions,  the  hinge  lace  is  most  satis- 
factory. There  are  many  forms  of  patent  belt  splices  and  wire 
lacing  on  the  market,  some  of  which  are  quite  satisfactory. 
Several  forms  permit  the  ends  of  the  belt 
to  be  separated  by  removing  a  rawhide 
pin  which  is  held  in  place  by  the  lace. 

Pulleys.  Pulleys  on  which  belts  run 
are  made  of  wood,  cast-iron,  or  steel. 
Wooden  pulleys  are  made  in  halves, 
arranged  to  be  easily  clamped  to  the 
shaft.  Cast-iron  and  steel  pulleys  are 
sometimes  made  in  the  same  manner. 

Wooden  pulleys  are  the  cheapest  and  are  very  conven- 


Fig.    201. 
way  to  lace  a  belt. 


Fig. 


wooden 


pulley. 


FARM  M0T0R8  323 

lent  to  attach,  but  are  not  so  durable  as  those  made  of  metal. 
Metal  pulleys  are  sometimes  covered  with  leather  in  order  to 
increase  the  friction  of  contact  with  the  belt.  Pulleys  from 
which  belts  are  not  to  be  shifted  should  have  a  crowned 
face.  This  will  cause  the  belt  to  keep  in  the  center  of  the 
pulley,  owing  to  the  fact  that  the  belt 
always  tends  to  run  to  the  highest  part 
of  the  pulley.  The  pulley  which  supplies 
the  power  is  generally  spoken  of  as  the 
driver,  and  the  one  receiving  the  power  is 
designated  as  the  driven  pulley. 

Calculating  the  Speed.  It  is  an  easy  Fig.  203^  a  piain 
matter  to  calculate  the  speed  or  the  diam-  ^^^^-iron  puiiey. 
eter  of  the  pulley,  when  it  is  remembered  that  the  diameter 
of  the  driving  pulley  multiplied  by  its  revolutions  per  min- 
ute is  equal  to  the  diameter  of  the  driven  pulley  multiplied 
by  the  number  of  its  revolutions  per  minute.  If  any  three 
of  the  four  quantities  involved  are  known,  the  fourth  may  be 
easily  obtained. 

Link  Belting.    A  common  method  of  transmitting  power 

in  agricultural  machinery  is  by  means  of 

link  belting  running  on  sprockets.     Link 

belting  is  positive  in  its  action,  as  there 

can  not  be  any  slippage.     It  is  very  strong, 

but  its  use  is  often  objectionable  on  account 

of  the  noise  which  it  makes  and  because 

Fig.  204^    A  split    it    cannot    be  operated    at   high    speed. 

iron  pulley.        xhcrc  are  several  styles  in  use;  in  some 

the  links  or  sections  are  made  of  malleable  iron,  and  in 

others  of  pressed  steel.     Again,  some  expensive  chains  are 

made  of  steel  rollers  with  short  steel  links  riveted  on  the  side. 

Rope  Transmission.    Where  power  is  to  be  transmitted 

some   distance    and  where    the   shafts    are    not    parallel 


324 


AGRICULTURAL  ENGINEERING 


ropes  running  over  grooved  pulleys  or  sheaves  may  be  used 

to   good  advantage.      Cotton  or   Manilla  ropes  are  used 

for  this  purpose.  These 
grooves  are  arranged  so 
as  to  cause  the  rope  to 
wedge  in,  thus  increasing 
the  effect  of  friction. 

Wire  Rope  or  Cable 
Transmission.  Where 
power  is  to  be  transmitted 
some  distance,  as  from 
one  building  to  another, 
wire  cables  can  be  used  to 
good  advantage.  The  pul- 
ley grooves  should  not 
wedge  the  wire  rope,  but 
instead  should  have  a  rub- 
ber filler  on  which  the 
rope  bears. 
Triangles  or  Quadrants.    The  power  from  a  windmill  may 

be  transmitted  to  a  distant  pump  . 

by  the  use  of  triangles  or  quad-  IZ~^^3 


Fig.  205.  An  example  of  the  trans- 
mission of  power  by  ropes  and  shafting. 
AAA    are   hangers. 


^ 


Z 


SN 


'A\ 


rants,  as  shown  in  Fig.  206.  If 
the  wires  are  long  they  are  sus- 
pended on  rocker  arms. 

Gearing.  A  very  common 
method  of  transmitting  power  in 
agricultural  machinery  is  by  means 

°  .  _,  .  „       Fig.  206.     Triangles  or  quad- 

01    gearmg.       The   construction    of  rants      used      in      transmitting 

the  teeth  is  a  matter  of  careful 

design,  since  they  must  be  made  to  run  smoothly  together. 
In  cast  gears  the  teeth  are  cast  to  shape,  while  in  cut  gears 
they  are  machine  made.     Cut  gears  are  generally  more  per- 


FARM  MOrORS 


325 


Fig.  207.  Spur  gear- 
ing. The  pinion  or 
small  gear  to  the 
right   is   "shrouded." 


feet,  but  are  more  expensive.      Gears  with  parallel  shafts 
are  called  spur  gears;  those  with  shafts  at 
an  angle  are  bevel  gears. 

Gears  transmit  power  positively,  as 
there  is  no  slippage.  A  small  gear  wheel 
in  mesh  with  a  large  one  is  often  spoken  of 
as  a  pinion. 

Friction  Gearing.  Friction  gearing 
transmits  power  by  the  friction  of  two  surfaces  in  contact. 
The  face  of  the  driven  pulley  is  usually  of  cast-iron,  and  that 
of  the  driver  is  of  paper  or  rawhide.  Fric- 
tion gearing  is  often  used  where  the  slip- 
page is  desirable  to  prevent  breakage  or  to 
start  heavy  loads. 

Shafting.    Power  may  be  transmitted 
from  one  point  to  another    by  means  of 
a  round  shaft,  to  which  pulleys,  sprock- 
ets, or  sheaves  may  be  attached.     This 
Fig.  208.    Bevel     shafting  is  usually  supported 
gear  ng.  by  haugcrs  carrying  bearings. 

Collars  or  rings  are  attached  to  the  shaft  to 
keep  it  in  place.  The  supporting  hangers 
should  be  near  the  pulleys,  or  at  such  short 
intervals  as  to  prevent  excessive  vibration  of 
the  shafting  while  running.  Usually  the  hang- 
ers are  placed  from  six  to  eight  feet  apart. 
The  power  which  the  shafting  will  transmit 
depends  upon  the  material  and  the  revolutions 
per  minute,  and  varies  directly  with  the  third 
power  of  its  diameter. 

A  common  formula  for  the  horsepower  of  the  shafting  is: 

H.  P.  = 

50 


Fig.  209.  Worm 
gearing. 


326 


AGRICULTURAL  ENGINEERING 


where  H.  P.  is  the  horsepower  transmitted,  D  is  the  diameter  of    the 
shafting,  and  R  is  the  number  of  revolutions  per  minute. 

The  above  formula  is  for  cold  rolled  steel  shafting,  the 
kind  in  general  use. 

QUESTIONS 

1.  Why  is  a  study  of  the  transmission  of  power 
an  important  feature  of  the  study  of  machinery? 

2.  How  is  power  transmitted  by  a  belt? 

3.  What  is  meant  by  "tight"  and  "slack" 
sides  of  the  belt? 

4.  Give  the  formula  for  estimating  the  horse- 
power capacity  of  a  leather  belt. 

5.  For  what  conditions  of  service  is  leather 
belting  adapted? 

6.  Describe  the  care  of  leather  belts. 

7.  For  what  kind  of  service  is  rubber   belting  best?      Canvas? 

8.  Explain  how  a  belt  should  be  laced. 

9.  Describe  the  various  kinds  of  pulleys  in  general  use. 

10.  Why  are  some  pulleys  crowned? 

11.  Explain  how  the  rotative  speed  of  one  pulley  may  be  obtained 
from  another. 

12.  Wherie  may  link  belting  be  used  to  good 
advantage? 

13.  What  kinds  of    ropes  are  used  in  rope 
transmission? 

14.  Under  what    conditions    should    a  wire    Fig.  211.    a  link  belt 
rope  or  cable  be  used? 


Fig.    210.      Friction 
gearing. 


or  chain  transmissions. 


15.  How  may  triangles  be  used  to  transmit  windmill  power? 

16.  What  is  the  difference  between  cut  and  cast  gears? 

17.  Describe  the  construction  and  action  of  spur  gearing. 

18.  Give  the  formula  for  the  horsepower  capacity  of  shafting. 


CHAPTER  LI 
THE  HORSE  AS  A  MOTOR 

Power  from  Horses.  The  horse  is  the  principal  source  of 
power  for  agricultural  purposes,  and  will  continue  to  be  for  an 
indefinite  length  of  time.  Considered  in  the  aggregate,  the 
horse  and  the  mule  furnish  a  large  part  of  the  total  power 
utilized  for  all  purposes.  In  the  United  States  there  are 
at  the  present  time  approximately  twenty-one  miUion  head  of 
horses  and  mules.  The  number  has  been  increasing  for  the 
past  sixty  years  at  the  rate  of  one-third  million  annually.  If 
all  these  were  at  work  at  one  time,  power  to  the  amount  of 
twelve  to  fifteen  miUion  horsepower  would  be  developed. 

Development.  The  prehistoric  horse  was  not  a  large 
animal ;  but  nature  and  man,  by  careful  mating  and  selection, 
have  produced  different  types,  each  suited  for  a  special  pur- 
pose, until  the  modem  horse  bears  but  little  resemblance  to 
the  original.  As  early  as  1740  b.  c.  the  horse  was  used  in 
war  for  transportation.  It  was  not  until  about  the  year 
1000  A.  D.  that  history  records  the  use  of  the  horse  in  the  field. 

The  development  of  the  horse  has  necessarily  been  very 
slow.  Greater  hardiness,  increased  size  and  strength, 
greater  beauty,  and  other  desirable  characteristics  were  rec- 
ognized by  men  who  made  careful  selections  for  mating  and 
awaited  results. 

The  horse  has  been  called  man's  best  friend  in  the  brute 
world,  and  the  ownership  of  a  good  horse  is  something  that 
any  man  can  be  proud  of.  Notwithstanding  the  fact  that 
the  horse  is  an  animated  thing,  it  is  the  chief  source  of  power 
on  the  farm,  and  may  properly  be  considered  a  motor.     It 

327 


328 


AGRICULTURAL  ENGINEERING 


differs  from  all  mechanical  motors  ii^  that  it  is  self-feeding, 
self-controlhng,  self-maintaining,  and  self-reproducing. 

Classification.  The  horse  in  one  sense  is  a  heat  motor, 
burning  fuel  in  the  shape  of  feed,  and  as  such  is  a  prime  mover. 
The  thermal  efficiency  of  a  horse  exceeds  that  of  an  average 
steam  engine,  but  does  not  equal  that  of  a  gas  or  internal- 
combustion  engine. 

Capacity  of  the  Horse.  The  amount  of  power  that  a  horse 
can  develop  depends  largely  upon  its  size  and  muscular  devel- 
opment.    Experiments  indicate  that  a  horse  exerts  a  pull  on 


Fig.    212. 


Testing  the    draft   of   a   horse.      Also  studying  the   effect   of 
the   height   and   length   of  the  hitch. 


his  traces  equal  to  from  1-10  to  1-8  of  his  weight  when  the 
working  day  is  not  allowed  to  extend  over  eight  to  ten  hours. 
The  speed  at  which  the  horse  is  able  to  produce  the  largest 
day's  work  is  from  2  to  2}4  miles  per  hour.  Thus  a  1500- 
pound  horse  walking  23^2  miles  per  hour  and  exerting  a  pull 
of  150  pounds,  will  develop  one  horsepower;  and,  furthermore, 
he  will  be  able  to  continue  this  for  a  period  not  longer  than  10 
hours.  An  increase  in  the  rate  of  travel,  or  an  increase  of 
the  effort  or  draft,  must  result  in  a  corresponding  decrease  in 
the  length  of  the  working  day. 


FARM  MOTORS  329 

Maximum  Capacity  of  the  Horse.  The  maximum  effort 
of  the  horse  for  a  short  time  may  exceed  his  own  weight.  In 
an  actual  test  a  horse  weighing  1550  pounds  and  puUing  on 
traces  at  an  angle  of  27  degrees  with  the  horizontal  exerted  a 
pull  of  1750  pounds.  A  draft  horse  may  exert  an  effort  of 
about  one-half  his  weight  while  walking  at  a  speed  enabling 
him  to  develop,  for  a  short  time,  as  much  as  four  or  five  horse- 
power. Such  trials  must  be  of  short  duration  and  be  followed 
by  periods  of  rest. 

The  fact  that  the  horse  is  such  a  flexible  motor,  being  able 
to  develop  power  much  in  excess  of  the  normal  rate,  is  cer- 
tainly a  great  advantage  for  traction  purposes,  where  the  load 
is  constantly  changing  because  of  the  condition  of  the  surface 
and  the  varying  grade.  Yet  this  fact  often  accounts  for  a 
serious  overloading,  resulting  in  an  injury  to  the  horse. 

Amoimt  of  Service.  The  horse  on  the  farm  does  not  do 
continuous  labor.  Investigation  in  Minnesota  indicates  that 
the  average  farm  horse  does  not  labor  for  more  than  1000 
hours  per  year.  The  useful  life  of  a  horse  is  usually  regarded 
as  ten  years. 

The  Size  of  Teams.  A  well-trained  horse  will  direct  his 
effort  at  the  command  of  his  master;  yet  the  manageable 
team  for  field  work  cannot  well  exceed  four  horses.  A  capable 
driver  can  drive  a  four-horse  team  practically  as  well  as  a  two- 
horse  team  and  manage  almost  any  of  the  implements  requir- 
ing four  horses.  It  is  true  that  larger  teams  than  four  horses 
are  in  use,  but  the  difficulty  connected  not  only  with  the 
driving  but  with  the  harnessing  and  hitching  will  hkely  pre- 
vent any  general  increase  of  the  size  of  the  field  team  beyond 
four  horses.  As  many  as  32  horses  have  been  driven  by  one 
man,  but  the  assistance  of  several  others  is  required  in  har- 
nessing and  hitching.  In  driving  these  large  teams,  which 
are  used  principally  on  the  combined  threshers  of  the  large 


330  AGRICULTURAL  ENGINEERING 

farms  of  the  West,  the  whole  team  is  controlled  largely  by  the 
two  leaders.  Thus,  if  a  24-horse  team  is  to  be  made  up,  the 
two  leaders  will  be  followed  by  four  horses  abreast  and  these 
by  the  others  arranged  six  abreast. 

The  Principles  of  Draft.  Although  horses  have  been 
used  as  draft  animals  since  the  dawn  of  history,  it  is  strange 
to  note  that  the  principles  of  draft  are  not  clearly  understood, 
many  points  being  open  to  argument.  The  individual 
horse  owner  has  not  felt  justified  in  making  exhaustive  experi- 
ments for  his  own  benefit,  and  no  professional  experimentahst 
has  found  it  possible  to  give  the  matter  attention.  Mr.  T. 
H.  Brigg,  of  England,  who  studied  the  subject  of  horse  haul- 
age, states  that  on  an  average  the  horse  is  made  to  waste  as 
much  as  50  per  cent  of  his  energies.  In  farm  practice  this 
would  evidently  not  be  true;  yet,  if  it  is  only  partly  true,  the 
horse  offers  a  fertile  field  for  profitable  investigation. 

The  amount  of  resistance  that  a  horse  can  overcome,  or 
the  draft  that  he  can  exert,  depends  upon  several  factors;  viz., 
his  weight,  height,  and  length,  his  grip  upon  the  road  surface, 
his  muscular  development,  and  the  direction  of  the  traces. 

Weight.  A  heavy  horse  has  several  important  advan- 
tages over  a  light  one.  In  the  first  place  his  adhesion  to 
the  road  surface  is  better, — there  is  less  tendency  for  him  to 
sHp;  and,  in  the  second  place,  with  the  heavy  horse  there  is 
less  tendency  in  pulling  to  lift  the  forefeet  from  the  ground. 

Height  and  Length.  The  latter  point  also  indicates  the 
advantage  that  a  long-bodied  horse  has  in  pulling.  The 
height  of  the  horse  may  or  may  not  be  to  his  advantage, 
depending  upon  the  height  of  hitch.  It  is  common  occur- 
rence to  see  the  efforts  of  a  horse  limited  by  his  weight  and 
length,  as  his  forefeet  are  hfted  from  the  ground  without 
permitting  him  to  exert  his  full  strength.  It  is  an  easy  matter 
to  demonstrate  that   a  horse   can  increase  his  maximum 


FARM  MOTORS  331 

effort  about  200  pounds  by  having  a  man  sit  astride  hi? 
shoulders.  Experienced  teamsters  with  hght  teams  often 
make  use  of  this  method  of  assistance  in  an  emergency  pull. 

Grip.  The  grip  of  the  horse  refers  to  the  hold  that  he 
secures  on  the  surface  of  the  road  or  ground.  Thus,  for 
example,  it  is  obvious  that  a  horse  without  sharp  shoes  could 
pull  but  little  on  ice.  In  like  manner  the  horse  is  often 
unable  to  obtain  a  sufficient  hold  on  hard  ground  or  pavement 
to  exert  his  full  strength. 

Muscular  Development.  It  is  necessary  that  the  horse 
have  large  and  powerful  muscles,  for  these  are  really  the 
motors  that  do  the  work.  The  object  of  the  breeder  of  draft 
horses  has  always  been  directed  toward  the  development  of 
the  muscles  as  well  as  the  increase  in  size. 

The  Proper  Angle  of  the  Traces.  The  proper  direction 
or  angle  of  trace  is  a  question  on  which  there  is  much  differ- 
ence of  opinion.  In  fact  there  are  two  phases  of  the  subject; 
first,  the  angle  of  trace  with  which  the  horse  will  labor  with 
the  most  comfort  and  ease;  and  second,  the  angle  of  trace 
which  will  move  any  load  with  the  least  force.  The  first  of 
these  is  the  most  difficult  to  study.  If  the  horse  can  realize 
that  certain  positions  of  the  hitch,  the  trace,  and  the  collar  are 
most  comfortable,  he  cannot  tell  his  master  so.  The  angle  of 
trace  has  a  very  decided  effect  upon  the  maximum  effort  of  a 
horse.  A  low  trace  has  a  tendency  to  pull  the  horse  into  the 
surface,  thus  adding  to  his  adhesion  and  grip  and  overcoming 
to  a  considerable  extent  the  tendency  to  lift  the  forefeet  from 
the  ground.  It  is  undesirable  to  maintain  a  low  trace  con- 
tinually, because  the  horse  is  compelled  to  carry  more  or  less 
of  the  load  when  less  effort  would  be  required  to  draw  it. 
For  maximum  speed  it  may  be  desirable  to  carry  a  part  of 
the  horse's  weight  on  the  truck,  and  the  racing  sulky,  whether 
purposely  or  not,  is  arranged  to  do  so. 


332  AGRICULTURAL  ENGINEERING 

Referring  to  the  angle  of  trace  for  the  minimum  draft,  it 
is  to  be  recognized  that  there  are  two  distinct  classes  of  imple- 
ments to  which  horse  labor  is  appUed:  (1)  those  intended 
primarily  for  moving  heavy  weights  from  place  to  place; 
.\  and  (2)  those  designed  to  work 

\  the  soil.    In  the  first  case  the  draft 

\  is  due  chiefly  to  the  friction  of 

\  •  the  machine  and  the   rolling  or 

\  sliding  resistance  of  the  surface. 

\  Thus,  in  Fig.  213,  it  is  to  be  noted 

— •^^\  that  a  certain  force,  W,  will  lift 

^ y  J ^^D^fi  /^  the  block,  A,  and  another  force, 
zzn/     F,  will  shde  it  on  the  surface. 


^'^the^angte  S^ieaBt'^dJ-af?*'''^  The  Icast  forcc,  howcvcr,  that  will 

produce  motion  lies  between 
these  two,  as  D,  and  its  direction  depends  upon  the  magni- 
tude of  each  of  the  other  two  forces.  In  mechanics  the 
angle  this  force  makes  with  the  horizontal  is  called  the  angle 
of  repose.  If  the  load  is  to  be  drawn  up  an  incline,  the 
proper  angle  of  trace  should  equal  the  ordinary  angle  plus 
the  angle  of  the  grade.  With  an  implement  like  the  plow,  the 
line  of  least  draft  extends  almost  directly  to  the  center  of  the 
place  where  the  work  is  being  performed. 

The  Length  of  Hitch.  Lengthening  the  hitch  does  not 
have  the  effect  that  it  is  generally  supposed  to  have.  The 
principal  effects  are  that  the  horse  does  not  have  as  complete 
control  over  the  load  and  that  the  angle  of  trace  is  changed. 
Lengthening  a  horizontal  trace  ten  or  even  fifty  feet  has 
practically  no  effect  upon  the  capacity  of  the  horse.  Men 
are  often  found  who  think  they  can  hold  a  horse  at  the  end  of 
a  50-  or  100-foot  rope.  A  trial  is  very  convincing  that  they 
cannot  do  so. 


FARM  MOTORS  333 

QUESTIONS 

1.  Why  is  the  horse  the  principal  source  of  farm  power? 

2.  To  what  extent  has  the  horse  been  developed  as  a  farm  motor? 

3.  In  what  way  does  the  horse  differ  from  mechanical  motors? 

4.  What  kind  of  motor  is  the  horse? 

5.  What  relation  is  there  between  the  weight  of  a  horse  and  the 
power   it   can   develop? 

6.  How  does  an  increase  in  the  speed  or  length   of  working  day 
affect  the  power  of  the  horse? 

7.  To  what  extent  can  a  horse  deliver  power  in  excess  of  the  nor- 
mal rate? 

8.  How  many  hours  of  service  does  an  average  farm  horse  render 
in    a   year? 

9.  Explain  how  horses  may  be  arranged  in  large  teams  for  heavy 
loads. 

10.  Upon  what  factors  does  the  amount  of  resistance  a  horse    can 
overcome  depend? 

1 1 .  How  does  the  height  and  length  of  a  horse  affect  the  resistance 
he  can  overcome? 

12.  What  is  meant  by  a  horse's  grip? 

13.  Explain  the  importance  of  muscular  development  in  a  draft 
horse. 

14.  Discuss  the  influence  of  angle  of  trace  on  draft. 

15.  Why  is  the  angle  of  least  draft  not  always  best? 

16.  How  does  the  length  of  hitch  affect  the  resistance  a  horse   can 
overcome? 


CHAPTER  LII 
EVENERS 

The  use  of  four-  or  five-horse  teaijis,  as  now  required  for 
many  implements,  introduces  many  perplexing  problems  in 
connection  wdth  the  hitch  and  the  eveners  for  dividing  the 
work  evenly  among  the  animals.  In  addition  to  the  increase 
in  the  size  of  teams  used  with  gang  plows,  disk  harrows,  drills, 
harvesters,  etc.,  the  tongue  truck  and  the  complicated  patent 
evener  have  been  introduced,  which  add  to  the  difficulty  of 
understanding  the  mechanics  involved. 

There  is  little  difficulty  in  dividing  the  load  equally 
between  the  members  of  a  two-horse  team.  The  doubletree 
may  be  of  any  reasonable  length,  depending  on  whether  it 
is  desired  to  work  the  horses  close  together  or  to  spread  them. 
To  divide  the  work  equally  between  two  horses,  the  end 
holes  for  attaching  the  singletrees  should  be  equally  distant 
from  the  center  hole.  The  wagon  doubletree  is  usually  44 
inches  long,  and  the  plow  doubletree  30  inches.  Large  horses 
cannot  be  worked  as  closely  as  smaller  ones.  It  is  undesir- 
able to  work  horses  too  closely,  as  all  are  worried  more  or  less 
by  not  having  sufficient  room. 

The  Placement  of  Holes.  When  the  horse  is  puHing  on 
the  end  of  an  evener,  his  advantage  or  leverage  is  equal  to 
the  perpendicular  distance  between  the  extended  line  of 
draft  and  the  line  of  resistance  passing  through  the  center 
hole,  or  the  fulcrum,  of  the  evener.  This  is  illustrated  in 
Fig.  214.  If  all  the  holes  in  the  evener  are  in  hne,  it  makes 
httle  difference  whether  or  not  it  is  kept  at  right  angles  to 
the  direction  of  movement.     If  the  center  hole  is  not  in  line 

334 


FARM  MOTORS  335 

with  the  two  end  holes,  then  the  load  is  divided  evenly  only 
when  the  two  horses  pull  evenly  together.  If  one  horse  pulls 
in  advance  of  the  other,  the  load  is  no  longer  evenly  divided. 
It  is  customary  to  place  the  end  holes  well  toward  the  rear 
edge  of  the  evener,  and  the  center  hole  well  toward  the  front 
edge.  This  placement  of  the  holes  adds  materially  to  the 
strength  of  wooden  eveners. 

When  the  holes  are  much  out  of  line  and  when  the  horses 
do  not  pull  evenly,  there  may  be  much  difference  in  the  efforts 
of  each.     In  Fig.  214,  which  shows  a  wagon  doubletree  as 


Fig.   214.     A  wagon  doubletree  illustrating  the  effect  of  not  having  the 
holes  for  the  clevis  pins  in  a  straight  line. 

actually  manufactured,  the  rear  horse  would  be  compelled 
to  pull  18.9  per  cent  more  than  the  leading  horse,  with  one 
end  of  the  doubletree  16  inches  in  advance  of  the  rear  end. 

Three-Horse  Eveners.  In  order  to  divide  a  load  among 
three  horses,  it  is  necessary  to  introduce  a  second  lever,  or 
some  other  device  to  take  its  place.  A  usual  method  of 
arranging  such  an  evener  is  shown  in  Fig.  217.  This  is  a 
combination  evener,  which  in  this  instance  does  not  space  the 
horses  evenly  but  indicates  the  general  arrangement  of  the 
three-horse  evener,  or  tripletree.     The  factory-made  triple- 


336 


AGRICULTURAL  ENGINEERING 


tree  usually  has  short  metal  levers  placed  over  a  wooden 
evener,  as  illustrated  in  Fig.  215.  This  gives  the  advantage 
of  a  shorter  hitch.     A  shorter  hitch  will  not  cause  an  appre- 


: — r--— f 


Fig.  215.     A  factory-made  tripletree  which  offers  advantage  of  a  close 

hitch. 

ciable  reduction  of  the  draft,  but  will  enable  the  team  to 
have  better  control  over  the  implement. 

Four-,  Five-,  and  Six-Horse  Eveners.  The  four-horse 
evener  is  usually  made  as  illustrated  in  Fig.  217.  This  con- 
sists in  a  four-horse  evener  with  two  doubletrees  attached. 

The  plain  five-horse  evener  is  made  as  shown  in  Fig.  216. 
The  dimensions  given  are  right  for  medium-sized  horses  when 
it  is  desired  to  work  them  together  as  closely  as  practical. 

There  has  been  a  decided  increase  in  the  use  of  the  14-inch 
gang  plow  during  recent  years.  This  plow  makes  a  load  too 
heavy  for  four  average  horses,  and  five  or  six  horses  should 
be  used.  It  is  undesirable  to  work  five  horses  abreast,  for, 
if  one  horse  walks  in  the  furrow  and  the  other  foiu*  on  the  land, 
the  load  or  line  of  draft  does  not  come  directly  behind  the 
center  of  the  team  and  there  will  be  much  undesirable  side 
draft.     It  is  better  to  put  two  horses  in  the  lead  and  use 


Fig.  216.     A  plain  five-horse  evener. 


eveners  such  as  those  shown  in  Fig.  217.  This  will  put  the 
team  directly  in  front  of  the  load  and  will  avoid  the  side  draft. 
Instead  of  the  short  levers  placed  under  the  rear  doubletree 


FARM  MOTORS 


337 


to  equalize  the  draft  between  the  leaders  and  the  two  horses 
directly  behind  them,  a  short,  vertical  evener  of  metal  or  a 
chain  and  pulley  may  be  used.  In  the  case  of  the  five-horse 
evener,  the  end  hole  for  the  single  horse  hitch  should  be 
four  times  as  far  from  the  center  hole  of  the  evener  as  the  end 
hole  for  the  four  horses  working  in  pairs.  In  case  of  the  six- 
horse  evener,  the  hitch  for  the  team  should  be  twice  as  far 
from  the  center  hole  as  the 
the    four-horse 


hole    for 
hitch. 

Plain  Eveners.  Simple 
or  plain  eveners  are  much 
to  be  desired.  There  is 
absolutely  nothing  to  be 
gained  by  a  complicated 
system  of  levers  and  tog- 
gle joints.  If  there  is  to 
be  an  equalization  of  the 
draft,  there  should  be  a 
flexible  hitch;  and  if  the 
evener  is  attached  to  the  Fig.  217. 
plow  or  other  implement 
at  more  than  one  point,  the  hitch  cannot  be  truly  flexible. 

Overcoming  Side  Draft.  With  four  horses  hitched 
abreast,  on  a  sulky  plow  the  line  of  draft  lies  outside  of  the 
line  of  resistance,  and  there  is  a  tendency  to  throw  the  front 
end  of  the  plow  away  from  the  land.  This  tendency  can  be 
partly  overcome  by  adjusting  the  front  furrow  wheel  in  such 
a  manner  as  to  pull  the  plow  toward  the  unplowed  land,  as 
previously  discussed.     (See  page  203.) 

The  tongue  truck  is  the  only  satisfactory  means  of  off- 
setting draft,  and  for  this  purpose  it  is  a  commendable  device. 
The  truck  should  be  provided  with  heavy  flanged  wheels 


flve- 


L    combination    three-, 
and  six-horse  evener. 


four- 


338 


AGRICULTURAL  ENGINEERING 


which  will  engage  the  surface  of  the  ground  and  give  a  thrust 
directly  across  the  line  of  draft.  This  arrangement,  no 
doubt,  adds  a  little  to  the  draft,  but  it  adds  much  to  the  con- 
venience of  handUng  the  team,  especially  on  the  harvester. 
When  three  horses  are  to  be  hitched  to  an  implement  with 
a  tongue  attached  in  the  line  of  draft,  much  may  be  accom- 
plished by  crowding  the  two  horses  on  one  side  of  the  tongue 

as  closely  together  as  pos- 
sible and  putting  the  sin- 
gle horse  out  as  far  as 
possible. 

Fig.  218  shows  an  at- 
tempt described  in  an 
agricultural  paper  some 
time  ago  as  a  successful 
method  of  overcoming  side 
draft  on  a  disk  harrow 
with  two  horses  on  one 
side  of  the  tongue  and  one 
on  the  other.  The  chain  pulls  back  precisely  the  same 
amount  that  it  pulls  the  one  side  of  the  disk  harrow  ahead. 


Fig,  218.  A  futile  attempt  to  remove 
side  draft  wtien  the  team  is  not  placed 
directly  in  front  of  the  load.  An  offset 
tongue  should   be  used. 


QUESTIONS 

1.  Why  is  it  more  important  to  study  eveners  now  than  formerly? 

2.  How  closely  should  horses  work? 

3.  Explain  how  the  placement  of  the  clevis  holes  of  a  doubletree 
may  influence  the  distribution  of  the  load. 

4.  Describe  the  construction  of  three-horse  eveners. 

5.  Explain  how  an  evener  may  be  arranged  to  hitch  five  or  six 
horses  to  a  plow. 

6.  Why  are  simple  or  plain  eveners  desirable? 

7.  What  is  the  best  way  to  overcome  side  draft? 

8.  Why  is  it  not  possible  to  remove  side  draft  by  running  a  chain 
across  a  machine? 


CHAPTER  LIII 
WINDMILLS 

Utility.  The  windmill  is  adapted  to  work  which  may  per- 
mit of  a  discontinuance  during  a  period  of  calm.  It  is 
adapted  to  regions  where  wind  of  a  velocity  sufficient  for  its 
operation  prevails  generally  throughout  the  year.  One  Hne 
of  work  which  will  permit  of  a  discontinuance  during  calm  is 
pumping,  and  for  this  reason  the  use  of  the  windmill  is  con- 
fined largely  to  this  work. 

When  properly  installed  and  working  under  proper  condi- 
tions, the  windmill  is  perhaps  one  of  the  most  economical  of 
all  motors.  As  a  source  of  energy  it  costs  nothing;  the  cost 
of  the  power  is  due  solely  to  the  interest  on  the  investment 
and  to  depreciation  and  repairs. 

Development.  The  use  of  windmills  dates  back  to  a 
very  early  time.  Wind  and  water  wheels  were  used  as  the 
first  source  of  power  long  before  heat  engines  were  thought 
of.  The  windmill  years  ago  reached  a  rather  high  stage  of 
development  in  Europe,  those  of  Holland  being  especially 
famous.  The  Holland  or  Dutch  mills  represent  a  distinct 
type,  in  that  there  were  usually  four  canvas  sails  mounted  on 
a  wooden  frame.  The  speed  was  regulated  by  varying  the 
amount  of  sail  surface  exposed  to  the  wind.  In  most  cases 
the  mill  was  turned  toward  the  wind  by  hand.  The  steel 
windmill  was  developed  in  the  United  Stated  about  1883. 

The  Wind.  Wind  is  simply  air  in  motion.  It  represents 
kinetic  energy,  and  the  windmill  obtains  power  from  it  by 
reducing  its  velocity,  causing  a  certain  amount  of  energy  to 

339 


340  AGRICULTURAL  ENGINEERING 

be  given  up.  It  is  easy  to  see  that  it  would  be  impossible  to 
reduce  the  velocity  to  zero  and  obtain  all  of  the  energy  of  the 
wind,  because  it  must  flow  past  the  windmill. 
'  Types  of  Mills.  There  are  many  types  of  windmills  on 
the  market,  and  they  may  be  classified  in  several  ways:  (1) 
by  the  material  used  in  construction,  (2)  by  the  type  of  con- 
struction, and  (3)  by  the  use  to  which  they  are  put.  For- 
merly the  wheels  were  made  almost  entirely  of  wood,  but 
steel  has  now  practically  displaced  wood.  It  is  claimed  by 
good  authorities  that  the  steel  wheel  is  more  efficient  and 
will  operate  in  a  lighter  wind  than  the  wooden  wheel,  owing 
to  the  thinness  and  the  shape  of  the  fans.  Windmills  may 
be  also  either  direct-stroke  mills  or  geared  mills.  Direct- 
stroke  mills  are  used  solely  for  pumping  purposes;  a  stroke  is 
made  with  each  revolution  of  the  wind  wheel.  In  order  to 
produce  a  mill  which  will  operate  in  lighter  winds,  gearing  is 
often  used  to  reduce  the  number  of  strokes  in  proportion  to 
the  number  of  revolutions  of  the  wheel.  Most  steel  mills  are 
now  geared  in  this  way. 

Windmills  used  solely  for  pumping  are  called  pumping 
mills,  and  the  power  is  transmitted  from  the  wind  wheel  by 
means  of  a  pumping  rod  having  a  reciprocating  motion. 
When  a  rotating  motion  is  desired  a  vertical  shaft  is  run  from 
the  mill  to  a  point  from  which  the  power  may  be  transmitted 
to  a  machine  by  any  of  the  more  usual  methods.  Such  a  mill 
delivering  its  power  by  a  rotating  shaft  is  said  to  be  a  power 
mill. 

Size  of  Mills.  The  size  of  windmills  is  indicated  by  the 
diameter  of  the  wheel.  Common  sizes  used  for  pumping 
purposes  are  8-  and  10-foot  wheels.  Power  mills  are  often 
built  much  larger,  with  wheels  20  or  more  feet  in  diameter. 
Wheels  of  large  diameter  must  be  made  very  strong  to  be 
able  to  withstand  the  wind,  and  the  extra  weight  thus 


FARM  MOTORS  341 

required  tends  to  reduce  the  efficiency.  Especially  large 
windmills  have  been  attempted,  but  they  have  not  been 
successful. 

Construction.  The  most  important  points  involved  in  the 
construction  of  a  windmill  are  the  strength  and  the  rigidity 
of  the  wind  wheel  and  the  durability  of  the  bearings  and  gears. 
The  wheel  must  necessarily  be  hght,  yet  it  must  be  carefully 
constructed  or  it  will  not  be  able  to  withstand  the  strenuous 
service  imposed  upon  it.  The  bearings  should  be  large,  of 
material  that  resists  wear,  and  be  easily  replaceable.  The 
gearing  should  also  be  of  liberal  dimensions. 

Lubrication.  One  of  the  most  important  features  of  the 
windmill  is  provision  for  adequate  lubrication  by  means  of 
magazine  oilers  or  lubricators,  one  filling  of  which  will  supply 
sufficient  lubrication  to  last  for  a  month  or  more.  Many 
mills  are  destroyed  by  failure  to  give  them  attention  in  this 
respect.  Some  makers  have  tried  to  provide  roller  bearings 
which  will  not  be  seriously  damaged  when  adequate  lubrica- 
tion is  not  provided. 

Regulation.  All  windmills  must  have  some  means  of  reg- 
ulating the  speed.  One  common  method  is  to  have  a  small 
side  vane  that  turns  the  wind  wheel  edgewise  to  the  wind  as 
the  velocity  of  the  wind  becomes  high.  Another  plan  is  to  set 
the  wheel  to  one  side  of  the  center  of  the  mast  on  which  it  is 
mounted,  when  the  unequal  pressure  tends  to  turn  the  wheel 
away  from  the  wind.  Again,  windmills  have  a  tendency  to 
turn  around  on  the  mast  as  the  rotating  speed  increases,  and 
this  tendency  is  made  u^e  of  in  regulating  speed.  In  some 
wheels  the  sections  are  hinged  and  are  connected  with  a 
centrifugal  governor  which  allows  them  to  be  turned  par- 
tially out  of  gear  as  the  wind  velocity  increases. 

Power  of  Windmills.  One  authority  concludes  that  the 
power  of  a  windmill  increases  as  the  cube  of  the  wind  velocity 


342 


AGRICULTURAL  ENGINEERING 


and  also  as  the  square  of  the  diameter  of  the  wheel.  A  later 
investigator  found  that  the  power  varied  more  nearly  as  the 
square  of  the  wind  velocity  and  about  the  1.25th  power  of 
the  diameter  of  the  wheel.  The  following  table,  reproduced 
from  the  work  of  Mr.  E.  C.  Murphy,  indicates  in  a  general 
way  the  amount  of  power  furnished  by  different  kinds  of  mills 
imder  different  conditions. 

Power  furnished  by  windmills  under  different  conditions. 


Name 

Kind 

Diameter 
in  feet 

Number  of 
sails 

Velocity  of 

wind  in 

miles  per 

hour 

Horse- 
power 

Monitor    . 

wood 
wood 
wood 
steel 
steel 
steel 

12 

14 

22.5 

12 

12 

14 

96 
102 
100-144 
18 
21 
32 

20 

20 
20 
20 
20 
20 

.357 

Challengo. 

.420 

Halliday 

.89 

Aermctor 

Ideal 

1.05 
.606 

Perkins 

.609 

Towers.  Like  the  windmill  proper,  the  tower  may  be 
built  either  of  wood  or  steel.  With  the  increase  in  the  cost 
of  wood  the  steel  tower  has  come  into  more  general  use.  The 
usual  height  of  tower  for  a  pumping  mill  varies  from  20  to 
60  feet.  The  wooden  tower  usually  has  four  posts  made  of 
4x4  or  5x5  material.  The  steel  tower  is  made  up  of  three  or 
four  posts  of  angle  irons.  The  steel  tower  is  now  almost 
universally  galvanized  for  protection  against  corrosion.  This 
is  also  true  of  the  steel  windmill.  It  is  desirable  to  have  the 
wheel  placed  well  above  all  obstructions  to  the  wind,  in  the 
way  of  trees,  buildings,  or  embankments.  A  small  wheel 
on  a  high  tower  is  regarded  as  better  than  a  large  wheel  on  a 
lower  tower  which  does  not  permit  the  wind  to  reach  the 
wheel  with  full  force. 


FARM  MOTORS  343 

QUESTIONS 

1.  To  what  kind  of  se«-vice  is  the  windmill  adapted? 

2.  Is  the  windmill  an  economical  motor? 

3.  How  long  has  the  windmill  been  used? 

4.  How  does  the  windmill  obtain  power  from  the  wind? 

5.  Can  the  windmill  obtain  all  the  energy  of  the  wind  which  strikes 


it? 


6.  How  may  windmills  be  classified? 

7.  What  is  the  difference  between  a  direct-stroke  and  a  back- 
geared  mill? 

8.  To  what  uses  may  a  power  mill  be  put? 

9.  How  is  the  size  of  a  windmill  designated? 

10.  What  are  some  of  the  important  features  of  the  construction 
Dt  a  windmill? 

11.  What  special  provision  for  lubrication  may  be  provided? 

12.  Describe  how  the  speed  of  a  windmill  may  be  regulated. 

13.  How  does  the  power  of  a  windmill  vary  with  the  diameter  of 
wheel? 

14.  How  does  the  power  of  a  windmill  vary  with  the  wind  velocity? 

15.  Describe  the  construction  of  the  windmill  tower. 


CHAPTER  LIV 

THE    PRINCIPLES    OF    THE    GASOLINE    OR    OIL 

ENGINE 

Relative  Importance.  The  general  introduction  of  the 
gasoHne  or  oil  engine  to  do  certain  classes  of  work  on  the  farm 
places  it  next  to  the  horse  in  importance  among  the  various 
farm  motors  now  in  use.  So  general  has  become  its  intro- 
duction and  so  varied  its  uses  that  it  is  now  imperative  that 
every  farmer  be  familiar  with  the  principles  of  its  operation 
and  the  essentials  of  its  successful  management. 

Classification  of  Motors.  The  gasoHne  or  oil  engine  is  a 
heat  engine,  since  its  function  is  to  convert  heat  or  heat 
energy,  hberated  by  the  combustion  of  gasoline  or  oil,  into 
mechanical  energy.  With  this  respect  it  is  to  be  classed 
with  any  motor  using  fuel  of  any  sort. 

The  gasoUne  or  oil  engine  is  an  internal-combustion  engine 
or  motor,  in  which  the  fuel,  along  with  a  sufficient  amount  of 
air  to  support  combustion,  is  ignited  inside  of  a  closed  cyhn- 
der.  The  steam  engine  might  be  styled  an  external-combus- 
tion engine,  in  that  the  combustion  takes  place  outside  of  the 
boiler  or  vessel  withholding  the  pressure  produced.  In  the 
internal-combustion  engine  the  heat  released  causes  an 
increased  pressure  of  the  gases  in  the  cylinder,  including  the 
products  of  combustion,  which  push  upon  the  piston  and 
cause  it  to  move  forward,  allowing  the  gases  to  expand  and 
do  work. 

Fuels.  The  gasoline  or  oil  engine  does  not  differ  essen- 
tially from  the  gas  engine,  the  difference  consisting  primarily 
in  a  device  called  the  carburetor,  provided  to  convert  the 

344 


FARM  MOTORS 


345 


liquid  fuel  into  a  gas.  Kerosene  and  fuel  oils  are  more  diffi- 
cult to  vaporize,  or  gasify,  than  gasoline,  and  for  that  reason 
a  special  carburetor  must  be  provided  when  they  are  used; 
but  in  other  respects  the  kerosene 
or  fuel  oil  engine  does  not  differ  es- 
sentially from  the  gasoline  engine. 
For  this  reason  it  is  entirely  cor- 
rect to  speak  of  all  internal-com- 
bustion engines  burning  either  gas 
or  liquid  fuels  after  this  manner  as 
gas  engines. 

The  gas  engine  is  very  simple, 
more  so,  in  fact, 
than  the  steam 
engine.  The 
accuracy  with 
which  the  va- 
rious functions 
must  be  perform- 
ed is  the  only  thing  which  prevents  the 
gas  engine  from  being  a  simple  affair  to  operate. 

Tjrpes.  There  are  two  general  types  of  gas  engines  on  the 
market.  These  are  known  as  the  two-cycle  and  the  four- 
cycle engines.  It  is  perhaps  more  proper  to  style  these  types 
as  the  two-stroke  cycle  and  the  four-stroke  cycle,  inasmuch  as 
two  and  four  strokes  of  the  piston  are  required  to  complete 
the  cycle  in  each  type,  respectively. 

A  cycle  is  a  term  used  to  designate  a  complete  set  of 
operations  which  must  take  place  in  every  engine  to  enable  it 
to  do  work.  The  appli  cation  of  work  or  the  hberation  of  energy 
in  the  gas  engine  is  intermittent.  This  is  true  of  all  recipro- 
cating motors,  but  more  operations  are  required  in  the  gaso- 
line engine  than  in  the  steam  engine.    The  four-stroke  cycle 


Fig.  220.  A  kero- 
sene carburetor  in  sec- 
tlon.  One  of  the  noz- 
zles is  for  water. 


Fiff.  219.  A  gasoline  car- 
buretor. The  gasoline  is 
vaporized  by  the  air  as  it  is 
drawn  past  the  nozzle. 


346 


AGRICULTURAL  ENGINEERING 


engine  is  the  more  simple  to  explain  of  the  two  types  and,  for 
that  reason,  should  be  considered  first.  It  is  to  be  assumed 
that  the  reader  understands  the  gas  engine  to  consist  of  the 
essential  parts  as  illustrated  in  Fig.  221.  These  parts,  as 
far  as  a  consideration  of  the  cycles  is  concerned,  consist  of  a 
cylinder  with  a  gas-tight  piston  attached  by  a  connecting  rod 
to  a  crank  on  which  the  fly  wheels  and  pulleys  are  attached, 
and  two  valves,  an  inlet  valve  to  let  the  gases  into  the 


2nd  Stroke 
(Compression) 


3rd  Stroke 
(Expansion  or  Working) 


4th  Stroke 
(Exhaust) 


Fig.   221. 


Illustrating  the  operations  which  take  place  in  a  four-stroke 
cycle  engine  to  obtain  a  power  or  working  stroke. 


cylinder  and  an  exhaust  valve  to  let  the  burnt  gases  out. 

Four-Stroke  Cycle.  The  four  strokes  in  the  four-stroke 
cycle  engine  are:     (SeeFig.  221.) 

First,  the  suction  stroke,  during  which  the  piston  increases 
the  volume  of  the  space  at  the  closed  end  of  the  cylinder  and 
thus  draws  into  the  cylinder  through  the  inlet  valve  a  charge 
of  vaporized  fuel,  and  enough  air  to  furnish  a  sufficient 
amount  of  oxygen  to  support  combustion. 

Second,  the  compression  stroke,  during  which  the  piston 
makes  a  return  stroke  and  compresses  the  gases  into  the  clear- 


FARM  MOTORS  347 

ance  space  at  the  end  of  the  cylinder.  This  operation  is 
necessary  in  order  to  get  the  full  power  out  of  the  fuel. 

Third,  the  expansion  stroke.  Just  before  the  end  of  the 
compression  stroke  the  ignitor  acts  so  that  combustion  takes 
place;  and  at  the  end  of  this  stroke  there  is  a  high  pressure 
ready  to  act  under  the  piston,  pushing  it  forward,  thus  doing 
the  work. 

Fourth,  the  exhaust  stroke,  during  which  the  piston 
returns  toward  the  closed  end  of  the  cyhnder  and  the  exhaust 
gases  are  pushed  out  through  the  exhaust  valve.  At  the  end 
of  this  stroke  the  piston  is  again  at  the  beginning  of  the  suc- 
tion stroke.  To  complete  the  cycle  it  is  noticed  that  two 
entire  revolutions  of  the  crank  shaft  and  fly  wheels  have  been 
required  and  that  only  one  of  these  four  strokes  is  a  working 
stroke,  or  a  stroke  during  which  the  engine  is  receiving  power. 
During  the  other  three  strokes  the  fly  wheels  must  furnish  the 
energy  to  keep  the  engine  in  motion. 

Two-Stroke  Cycle  Engine.  The  two-stroke  cycle  engine 
is  an  attempt  to  increase  the  number  of  working  strokes  by 
providing  an  auxiliary  chamber  in  which  the  gasoline  or  fuel 
mixture  is  given  such  an  initial  compression  that  at  the  end 
of  the  exhaust  stroke  these  fresh,  unburned  gases  under  com- 
pression readily  displace  the  burned  gases.  This  displace- 
ment takes  place  so  quickly  that  it  is  possible  to  compress  the 
fresh  gases  during  the  return  stroke.  These  operations  are 
shown  in  Fig.  222,  which  shows  in  outline  an  engine  using  the 
crank  case  as  a  compression  chamber.  Owing  to  the  larger 
number  of  working  strokes  for  a  certain  rotative  speed  the 
two-cycle  engine  has  the  advantage  of  light  weight. 

As  the  events  in  the  two-cycle  engine  occur  in  every  revo- 
lution instead  of  once  in  two  revolutions,  the  two-cycle  engine 
is  of  more  simple  construction.  A  secondary  shaft  operated 
by  a  reducing  gear  for  opening  the  valves  and  making  one 


348  AGRICULTURAL  ENGINEERING 

revolution  to  two  of  the  crank  shaft,  is  not  required,  and  in 
many  engines  the  main  valves  are  dispensed  with  by  making 
the  piston  uncover  ports  or  openings  in  the  cylinder  walls  for 
the  admission  of  fresh  gases  and  the  escape  of  those  burned. 
This  simplicity  of  construction  enables  the  two-cycle  engine 


Fig.  222,  Illustrating  the  operations  which  take  place  in  the  two-stroke 
cycle  engine.  A,  suction  into  crank  case,  B,  compression  in  crank 
case.  C,  compression  in  cylinder  combined  with  A.  D,  expansion  in 
cylinder  combined  with    B.    (From  Farm  Machinery  and  Farm  Motors.) 

to  be  built  and  sold  at  a  lower  cost  than  the  four-stroke  cycle 
engine. 

On  the  other  hand,  the  two-cycle  engine  does  not  operate 
with  the  same  economy  in  fuel  consumption  as  the  four-stroke 
cycle.  If  the  cylinder  diameter  is  large,  the  mixing  of  the 
fresh  and  burned  gases  is  so  great  that  there  cannot  be  the 
best  scavenging  or  cleaning  of  the  burned  gases  from  the  cylin- 
der without  a  loss  of  unburned  gases  to  the  exhaust.  Very 
large  engines  are  made  on  the  two-cycle  plan  by  introducing 
an  auxiUary  air-compression  cyhnder  which  blows  air  to  clean 
out  the  burnt  gases. 

The  two-cycle  engine  is  a  Httle  more  difficult  to  manage, 
as  a  rule,  and  the  carburetor  and  the  ignition  system  are  more 
susceptible  to  slight  misadjustments.  This  is  no  doubt 
largely  due  to  the  fact  that  there  cannot  be  as  sharp  a  suction 
upon  the  carburetor  as  may  be  had  with  the  four-cycle  engine. 


FARM  MOTORS  349 

This  sharp  suction  is  very  valuable  in  assisting  to  vaporize 
the  fuel  by  the  rapid  rush  of  air  through  the  carburetor. 

QUESTIONS 

1.  Why  is  the  gasoline  or  oil  engine  an  important  farm  motor? 

2.  To  what  class  of  motors  does  the  gasoUne  or  oil  engine  belong? 

3.  Why  is  the  gas  or  oil  engine  an  internal-combustion  engine? 

4.  Why  is  it  correct  to  speak  of  the  gasoline  or  oil  engine  as  a  gas 
engine? 

5.  Describe  the  four-stroke  cycle  type  of  engine. 

6.  Describe  the  two-stroke  cycle  type  of  engine. 

7.  Compare  the  advantages  of  the  two-stroke  and  four-stroke 
cycle  engines. 


CHAPTER  LV 
ENGINE  OPERATION 

Essentials  of  Operation.  Someone  has  said  that  there 
are  four  features  of  the  action  of  the  gasoUne  or  oil  engine 
which  must  be  right  or  the  engine  will  not  run  and  furnish 
power;  and  if  they  are  right,  the  engine  will  run  in  spite  of 
everything,  assuming  for  the  time  being  that  the  working 
parts  are  in  such  adjustment  as  to  permit  of  free  move- 
ment.    These  essential  features  are: 

1.  Proper  mixture  of  gases. 

2.  Compression. 

3.  Ignition. 

4.  Correct  valve  action. 

The  Gas  Mixture.  During  the  suction  stroke  of  the 
piston  the  cyhnder  is  drawn  full  of  air  mixed  with  a  suffi- 
cient amount  of  fuel  vapor.  The  amount  of  air  and  fuel 
vapor  must  be  in  about  the  correct  proportion  or  the  mixture 
will  not  burn.  For  instance,  if  there  be  httle  fuel  or  if  it  be 
improperly  vaporized,  the  mixture  will  not  be  ignited  by  the 
spark  produced  by  the  igniter.  On  the  other  hand,  the  mix- 
ture will  not  burn  if  the  proportion  of  fuel  vapor  be  too  large ; 
oxygen  of  the  air  must  be  present  to  support  combustion. 
Pure  fuel  vapor  or  gas  will  not  burn,  nor  will  very  rich  mix- 
tures. 

Now  the  range  of  proportions  in  which  the  air  and  fuel 
vapor  may  be  mixed  and  still  give  a  combustible  mixture  is 
quite  limited,  and  the  range  of  mixtures  which  will  give  a 
good,  strong  working  stroke  is  still  more  limited.  The  richest 
mixture  that  will  burn  has  been  stated  by  one  authority  to 

3o0 


FARM  MOTORS  351 

be  about  one  part  of  gas  or  fuel  vapor  to  four  parts  of  air. 
The  same  authority  gives  one  part  of  fuel  vapor  to  fourteen 
parts  of  air  as  being  the  leanest  mixture  that  will  burn. 

It  is  to  be  remembered  in  this  connection  that  of  every 
one  hundred  parts  of  air  only  23  parts  are  oxygen;  and  it  is 
the  oxygen  that  supports  combustion.  The  largest  constitu- 
ent of  air,  nitrogen,  composes  about  77  parts  of  the  one 
hundred.  Nitrogen  is  entirely  inert,  and 
in  the  gasoline  engine  cylinder  it  occu- 
pies space  which  would  be  more  desir- 
ably filled  with  gasoline  and  oxygen. 

In  changing  from  a  liquid  to  a  vapor, 
the  fuel  is  increased  in  volume  some  600 
to  1000  times.  This  means  that  the 
ratio  of  the  volume  of  liquid  fuel  used  to 
that  of  air  must  vary  from  1  to  8,000  up  ,Z%,''\,r^X,,Z: 
to  about  1  to  16,000.  From  this  we  see  l^^^oS  sJ^^ueT.Zl 
why  the  carburetor  of  the  gasoUne  engine  a^"ulary  'air "  vaive 
is  such  a  sensitive  affair.  ^un^at  wgh  s7elT 

Not  only  must  the  ratio  of  fuel  to  air  be  quite  constant, 
but  the  difficulties  encountered  are  magnified  by  the  fact  that 
the  mixing  must  take  place  between  colorless  gases  and  "sight 
unseen"  inside  the  engine  cylinder.  The  gas  engineer  must 
resort  to  tests  that  will  show  the  condition  of  the  mixture. 

If  the  mixture  can  be  adjusted  until  it  will  burn,  then  the 
adjustment  for  the  proper  mixture  is  easy.  A  too  rich  mix- 
ture is  indicated  by  black  smoke  from  the  exhaust;  and  one 
too  lean,  by  a  sharp,  prolonged  exhaust,  indicating  a  slowly 
burning  mixture.  The  smoke  of  a  too  rich  mixture  is  black, 
while  that  caused  by  too  much  lubricating  oil  is  blue. 

When  the  engine  is  provided  with  a  hit-or-miss  governor, 
the  needle  or  supply  valve  should  be  adjusted  to  require  the 
least  number  of  explosions  necessary  to  furnish  a  given 


352  AGRICULTURAL  ENGINEERING 

amount  of  power  and  then  be  slightly  closed.  The  adjust- 
ment which  gives  the  least  number  of  explosions  does  not  give 
the  most  economical  setting  of  the  needle  valve,  and  that  is 
why  the  valve  should  be  closed  slightly. 

Testing  the  Mixture.  The  most  perplexing  trouble 
comes  when  it  is  impossible  to  get  a  single  explosion.  In  this 
case  certain  tests  must  be  made  to  determine  whether  the 
cylinder  is  flooded  with  fuel  or  whether  there  is  not  enough 
gasohne  vapor  present  to  make  an  explosive  mixture.  Of 
course,  tests  should  be  made  to  determine  that  the  ignition 
system  is  perfect  and  that  an  explosive  mixture  would  be 
ignited  if  there  should  be  one  in  the  engine  cylinder. 

One  plan  to  follow  is  to  shut  off  the  fuel  supply  and  clear 
the  cylinder  thoroughly  of  all  gasoline  by  turning  the  engine 
over  several  times.  This  being  done,  an  entirely  new  attempt 
to  start  the  engine  will  usually  meet  with  success. 

A  test  may  be  made  of  the  nature  of  the  mixture  in  the 
cyUnder  by  holding  a  lighted  match  to  the  reUef  cock  as  the 
engine  is  turned  over.  A  rich  mixture  will  burn  as  it  comes 
in  contact  with  the  air;  an  inflammable  mixture  will  snap  back 
into  the  cylinder;  and  a  mixture  which  is  too  lean  will  not 
burn  at  all. 

The  Compression.  It  is  necessary  that  a  gasohne  engine 
compress  the  mixture  of  gasohne  vapor  and  air  before  ignition 
or  the  full  power  of  the  fuel  will  not  be  obtained.  Failure 
to  secure  compression  is  usually  due  to  leaks,  either  past  the 
piston  or  through  the  valves. 

Leaks.  Piston  rings  are  provided  to  make  a  gas-tight  fit 
between  the  piston  and  the  cylinder.  Sometimes  these  rings 
become  stuck  in  their  grooves  by  charred  oil  and  do  not 
spring  out  against  the  cylinder  walls  as  they  should.  When 
this  happens,  which  usually  is  due  to  the  use  of  poor  lubricat- 
ing oil,  the  rings  should  be  thoroughly  cleaned.    Where  the 


FARMMOTORSS  353 

trouble  is  not  serious,  the  rings  may  be  loosened  by  feeding  in 
kerosene  through  the  lubricator.  When  the  rings  become 
worn,  they  should  be  replaced. 

Leaks   may   also   take   place   past   the   valves.     Often 
charred  oil  will  lodge  on  the  valve  seat,  preventing  it  from 


COMPRESSION 
SPACE 


Fig.  224.     A  sectional  view  of  a  gas  engine  cylinder,  showing 
the  cylinder  volume  and   clearance  space. 

closing  tightly.  Cleaning  will  often  overcome  this  difficulty; 
but  when  scored  or  pitted,  the  valve  must  be  ground  on  its 
seat  with  emery  and  oil  until  a  perfect  fit  is  again  secured. 

QUESTIONS 

1.  What    are    the   four    fundamental    essentials    of    gas    engine 
operation? 

2.  What  is  meant  by  an  explosive  mixtuie? 

3.  What  are  some  of  the  difficulties  encountered  in  obtaining  an 
explosive  mixture? 

4.  What  are  the  indications  of  a  rich  mixture?     A  lean  mixture? 

5.  Explain  how  the  quality  of  the  mixture  may  be  tested. 

6.  How  does  compression  influence  the  power  of  an  engine? 

7.  What  are  the  common  causes  for  the  loss  of  compression? 


12— 


CHAPTER  LVI 
GASOLINE  AND  OIL  ENGINE  OPERATION  (Continued) 

Ignition.  The  burning  of  the  fuel  in  a  steam  plant  is 
continuous  from  the  time  of  kindling  the  fire  until  the  plant  is 
shut  down.  In  the  gasoline  engine  the  fire  is  quickly  extin- 
guished, lasting  but  a  part  of  one  stroke  of  the  piston,  necessi- 
tating the  igniting  of  additional  fuel  as  it  is  taken  into  the 
cylinder.  It  is  easy  to  see  that  if  for  any  reason  there  is  a 
failiu-e  to  ignite  the  fresh  fuel,  no  power  will  be  obtained  from 
that  particular  cyHnder.  As  in  the  case  of  failure  to  secure 
the  proper  mixture  and  compression,  the  gas  engine  will  not 
operate  unless  each  charge  is  successfully  ignited. 

Development.  As  indicated,  the  firing  of  the  charge  in 
the  cylinder  is  spoken  of  as  the  ignition,  and  the  devices  that 
accomplish  it,  the  ignition  system.  One  of  the  principal  diffi- 
culties encountered  by  the  early  inventors  in  developing  the 
gas  engine  was  that  of  securing  ignition.  The  early  attempts 
consisted  largely  in  carrying  an  open  flame  into  the  cylinder 
by  means  of  suitable  valves.  Later,  the  hot  tube  was  used 
generally,  and  is  to  some  extent  at  the  present  time.  The 
hot-tube  igniter  consisted  of  a  short  length  of  pipe  screwed 
into  the  compression  space  and  kept  at  red  heat  by  means  of 
an  outside  flame.  During  compression  the  unburned  gases 
pushed  the  burned  gases  up  into  the  tube  until  the  fresh  fuel 
came  in  contact  with  the  hot  surface  of  the  tube,  causing 
ignition.  It  is  not  possible  to  regulate  the  time  of  the  ignition 
with  the  hot  tube  as  accurately  as  desired,  and  when  used  \^rith 
a  small  engine,  at  least,  the  fuel  required  to  keep  the  tube  hot 
is  often  an  important  part  of  the  entire  cost  of  operation. 

354 


FARM  MOTORS 


355 


These  shortcomings  on  the  part  of  the  hot  -tube  igniter,  and 
the  rapid  development  of  the  electric  igniter  have  caused  the 
general  abandonment  of  the  former. 

There  are  two  general  classes  of  electric  ignition  systems 
in  general  use.  These  systems  are  generally  known  as  the 
''make-and-break"  system  and  the  "jump-spark"  or  high- 
tension  system.  Each  of  these  systems  has  its  advantages. 
The  make-and-break  system  is  used  largely  in  connection 
with  stationary  engines,  while  the  jump-spark  is  used  with 
variable-speed  motors,  like  the  automobile. 

The  Make-and-Break  System.  In  the  make-and-break 
system  of  electric  ignition  two  electrodes  or  points  are  pro- 


^pCKrk  Co// 


I^n/for 


^iy.Uery  of  Dry  Cells 


rig.  225,  Sketch  showing  the  wiring  and  essential  parts  of  a  make- 
and-break  system  of  ignition.  Four  standard  dry  cells  form  the  usual 
battery  instead  of  six  as  shown. 

vided  in  the  compression  space  of  the  engine  cylinder,  and  are 
insulated  from  each  other  in  such  a  way  that  an  electric  cur- 
rent will  not  flow  through  them  unless  they  are  made  to 
touch  each  other.  When  an  electric  current  is  broken,  there 
is  a  tendency  to  produce  a  spark  at  the  point  where  the  separa- 
tion takes  place.  By  placing  a  spark  coil  in  the  circuit  the  size 
of  the  spark  may  be  much  increased.    The  system  consists 


856  AGRICULTURAL  ENGINEERING 

primarily  in  providing  a  source  of  electricity  and  suitable 
mechanism  to  bring  the  points  together  at  the  proper  time 
and  to  separate  them  at  the  proper  time  for  the  sparks  so  pro- 
duced to  fire  the  mixture  in  the  cyUnder. 

The  make-and-break  system  does  not  use  high-tension  or 
high-voltage  electricity.  Voltage  corresponds  to  pressure, 
or  abiUty  of  the  electricity  to  overcome  resistance.  For  this 
reason  the  make-and-break  system  does  not  require  such 
careful  insulation  as  does  the  high-tension  system.  There 
are,  however,  the  moving  parts  inside  of  the  cylinder,  and 
the  mechanism  operating  it  is  such  that  it  is  not  convenient 
to  make  provision  for  varying  the  time  of  ignition.  Failure 
on  the  part  of  the  make-and-break  system  may  be  generally 
traced  to  failure  in  the  source  of  current,  or  to  a  break-down 
of  insulation.  There  are  many  other  minor  causes  of  failure, 
but  space  does  not  permit  a  discussion  of  them  here. 

Testing  the  Make-and-Break  System.    When  an  engine 

fails  to  start,  a  test  should  be  made  of  the  ignition  system. 

-^— —--:.- — — n    This  is  generally  done  by  making  and  break- 

^j^Hj^^        ing  the  circuit  by  hand  outside  of  the  engine 

^^^Hfl|^      cylinder,  and  judgment  is  then  passed  upon 

^^^(P^      the  size  of  the  spark  as  to  whether  or  not 

it  is  sufficient  to  ignite  the  charge.     After 

makl-a  n" d-'break     the  iusulation  on  the  wircs  becomes  worn 

and  damaged,  there  may  be  an  escape  of 

electricity  without  passing  through  the  igniter  points.     The 

igniter  points  may  become  covered  with  scale,  oil,  or  dirt 

which  will  prevent  the  electricity  from  passing  from  one  to 

the  other  when  desired.     Often  the  movable  points  fail  to 

work  freely,  owing  to  lack  of  oil,  preventing  the  sharp,  quick 

separation  of  the  points,  which  is  quite  necessary  to  secure  a 

good,  lac  spark. 


FARM  MOTORS 


357 


The  Jump-Spark  System.  The  jump-spark  system  does 
not  have  any  working  parts  inside  of  the  cyHnder,  where  they 
are  exposed  to  the  high  temperature  there  present.  The 
mechanism   is  such    that  ^  „„„.,.,^_^ 

it  is  convenient  to  vary      "^^  — fi—-^" 

the  time  of  ignition  when 
this  is  used  to  regulate  the 
speed  of  an  engine,  as  it  is 
in  the  case  of  the  automo- 
bile engine.  The  jump- 
spark  system  requires  the 
use  of  an  induction  coil, 

'         Fig.   227.     Sketch  showing  the  essential 
which,   when  connected  to     parts    of    a    jump-spark   system    of    igni- 

one  of  the  usual  sources  of 

electricity,  increases  the  voltage  to  such  an  extent  that  when 
suddenly  cut  off  the  new  or  induced  current  jumps  a  small 
gap.  The  usual  spark  plug  is  only  a  provision  for  placing 
this  gap  inside  of  the  engine  cylinder.  Owing  to  the  high 
voltage  of  the  jump-spark  system,  certain  wires  must  be 
very  carefully  insulated  in  order  that  the  gap  of  the  spark 
plug  shall  be  the  path  of  least  resistance  for  the  current 

to  escape. 

Testing.  It  has  been 
suggested  that  tests  be 
made  with  the  make-and- 
break  system  of  ignition 
to  determine  whether  or 
Fig.  228.   A  jump-spark  or  induction  coil  not  the  system  is  in  work- 

dissembled  to  show,  construction.  j^^  ^^^^^  ^^^^   ^^.^^^j^    j^ 

encountered.  A  convenient  way  of  testing  the  jump-spark 
system  is  to  remove  the  spark  plug  and  lay  it  upon  the 
cylinder  and  manipulate  the  circuit-breaking  mechanism  by 
hand.     If  a  good  spark  be  obtained,  it  may  be  assumed 


HI  Hl^   r  ^  1 

A  a  c  J" 


358 


AGRICULTURAL  ENGINEERING 


Fig.  229.  A 
spark  plug  in 
section,  show- 
ing construc- 
tion. 


that  the  trouble  Ues  elsewhere  than  in  the  ignition  system. 
The  Batteries.  Any  form  of  electric  ignition  requires  a 
source  of  electricity.  One  of  the  most  general  forms  on  the 
market  is  the  dry-cell  battery.  It  represents, 
perhaps,  the  cheapest  source  of  electricity,  as 
far  as  first  cost  is  concerned.  When  the  cells  are 
able  to  furnish  a  sufficient  quantity  of  electricity, 
they  are  very  satisfactory.  One  of  the  most 
perplexing  features  of  the  use  of  dry-cell  bat- 
teries is  the  matter  of  determining  when  the 
cells  are  exhausted,  as  there  is  no  change  in 
the  outside  appearance. 
There  are  instruments,  known 
as  ammeters,  which  enable 
one  to  determine  how  much  current  a  dry 
cell  will  furnish;  and  where  many  dry  cells 
are  used,  this  instrument  should  alwaj^s 
be  on  hand  to  detect  exhausted  cells.  If 
an  instrument  is  not 
available,  the  strength 
of  the  cells  must  be 
judged  from  the  size 
and  character  of  the  sparks  produced  when 
tested. 

Storage  batteries  make  a  very  satis- 
factory source  of  electric  current  for  igni- 
tion, but  provision  must  be  at  hand  for 
recharging  when  they  become  exhausted. 
Fig.  231.   An  oscii-        MagHetos  and  Dynamos.    Perhaps  the 

lating     magneto     on  ^  ^  •'  i.     i  • 

tiemonstration  stand,  most  Satisfactory  source  of  electric  current 
for  gasoHne  engine  ignition  is  the  magneto  or  dynamo, 
which  is  a  small  instrument  for  making  electricity  by  me- 
chanical means.    Indications  are  that  it  will    be  only  a 


Fig. 


230.      A    storage 
battery. 


FARM  MOTORS 


359 


comparatively  short  time  until  the  magneto  will  be  consid- 
ered a  necessary  part  of  the  equipment  of  the  gas  engine. 
At  the  present  time  the  magneto  is  regarded  as  almost  a 
necessity  in  the  operation  of  the  automobile  engine.  In 
selecting  a  magneto  or  dynamo,  care  should  be  taken  to  see 
that  it  is  well  adapted  to  the  service  required  and  that  it  is 
properly  installed. 

Valve  Action.  The  last  of  the  four  essentials  for  the  suc- 
cessful operation  of  the  gas  engine  is  proper  valve  action,  or 
the  correct  timing  of  the  valves.  It  is  obvious,  after  what 
has  already  been  written 
on  this  subject,  that  the 
valves  must  open  at  the 
proper  time  to  let  the 
gases  into  the  cylinder, 
close  at  the  proper  time 
to  withhold  them  for  the 
power  stroke,  and  open 
again  to  let  the  burned 
gases  escape.  The  suc- 
tion or  inlet  valve  on 
farm  engines  is  usually 
operated  by  the  suction  produced  by  the  piston  during  the 
suction  stroke,  and,  outside  of  the  adjustment  of  the  light 
spring  which  closes  the  valve,  it  is  self-timing.  The  exhaust 
valve  should  open  before  the  end  of  the  expansion  stroke, 
to  allow  the  free  escape  of  the  burned  gases,  and  must 
close  at  about  the  end  of  the  exhaust  stroke.  The  exhaust 
valve  for  an  average-sized  engine  is  made  to  open  when 
the  crank  is  about  30°  from  dead  center,  but  the  time  will 
vary  with  the  speed  and  size  of  the  engine.  Directions 
should  be  found  with  each  engine  for  the  setting  of  the 
valves. 


..^■n 

t 

« 

IB^^ 

> 

Fig.    232. 


A    dynamo    called    the    Auto- 
sparker. 


360  AGRICULTURAL  ENGINEERING 

QUESTIONS 

1.  Why  is  ignition  so  important  to  the  success  of  a  gas  engine? 

2.  Describe  the  hot-tube  igniter. 

3.  What  are  the  names  of  the  two  systems  of  electric  ignition? 

4.  Describe  the  make-and-break  system  of  ignition. 

5.  Explain  how  this  system  may  be  tested. 

6.  Describe  the  jumi)-spark  system  of  ignition. 

7.  Explain  how  this  system  may  be  tested. 

8.  Describe  the  use  of  dry  cells  as  a  source  of  current  for  electric 
ignition. 

9.  How  does  the  dynamo  or  magneto  furnish  electricity  for  igni- 
tion purposes? 

10.  Why  is  valve  action  or  timing  important? 

11.  Describe  in  a  general  way  when  the  inlet  and  exhaust  valves 
should  open  and  close  with  reference  to  the  position  of  the  crank. 


CHAPTER  LVII 
SELECTING  A  GASOLINE  OR  OIL  ENGINE 

The  selection  of  a  gasoline  or  oil  engine  for  the  farm  is  not 
easy,  owing  to  the  many  features  of  the  problem  involved. 
First,  there  is  the  size  or  horsepower  to  be  decided;  second, 
the  type,  involving  such  features  as  weight  and  speed;  third, 
the  mounting;  and  fourth,  the  quality  of  the  engine. 

The  Size.  The  gasoline  or  oil  engine  is  used  on  the  farm 
for  many  purposes  at  the  present  time,  and  the  power 
requirements  for  these  various  purposes  differ  widely.  The 
following  list  gives  the  more  common  uses  for  the  gasoline 
engine  and  indicates  the  approximate  amount  of  power 
required : 

Washing  machine,  Y2  to  1  H.P. 

Churn,  1  to  J^  H.P. 

Pump,  3^  to  2  H.P. 

Grindstone,  3^  to  2  H.P. 

Electric  generator,  1  H.P.  or  more. 

Feed  mill,  3  H.P.  or  more. 

Portable  elevator,  3  to  5  H.P. 

Corn  shelier,  2  H.P.  or  more. 

Ensilage  cutter,  5  to  25  H.P. 

Threshing  machine,  6  to  50  H.P. 

It  is  to  be  noticed  that  the  first  four  machines  require  a 
rather  small  engine,  while  the  others  either  require  consider- 
ably more  power,  or  they  may  be  operated  more  advan- 
tageously when  of  a  size  suitable  to  a  medium-sized  engine. 
The  feed  grinder  may  be  obtained  in  almost  any  size;  but 
where  magazine  bins  are  not  provided  and  where  it  is  expected 

361 


362  AGRICULTURAL  ENGINEERING 

to  give  the  grinder  attention  while  in  operation,  a  large  one  is 
a  decided  advantage.  A  grinder  using  six  to  twelve  horse- 
power will  grind  feed  at  such  a  rate  that  one  man  will  have  all 
he  can  do  to  provide  grain  for  the  hopper  and  to  shovel 
away  or  bag  the  ground  feed. 

Ensilage  cutters,  when  provided  with  a  pneumatic  ele- 
vator or  blower,  require  considerable  power,  and  it  is  an 
advantage  to  have  a  machine  which  will  take  undivided 
bundles  of  fodder.  To  operate  such  a  machine,  a  12-horse- 
power  engine,  or  larger,  is  required. 

There  are  small  threshing  machines  on  the  market  which 
require  little  power  for  their  operation,  and  are  no  doubt  a 
success  where  a  small  amount  of  grain  is  to  be  threshed.  The 
small-sized  machines,  equipped  with  the  modern  labor-saving 
attachments,  such  as  the  self-feeder  and  the  wind  stacker, 
require  about  12  horsepower  for  their  successful  operation. 
The  other  larger  machines  mentioned  may  be  procured  in 
almost  any  size  to  accommodate  the  size  of  the  engine  pur- 
chased. 

From  this  analysis  it  would  seem  that  there  are  two  classes 
of  work  on  the  average-sized  farm  which  require  two  sizes 
of  gasoline  engines  if  the  work  is  to  be  performed  economic- 
ally. A  certain  portion  of  the  fuel  used  by  an  engine  is 
needed  to  overcome  the  friction  within  the  engine  itself,  or 
to  operate  it.  After  enough  fuel  is  furnished  to  keep  the 
engine  in  motion,  the  additional  fuel  used  is  converted  into 
useful  work.  The  percentage  of  the  total  fuel  required  to 
operate  the  engine  proper,  when  under  full  load,  is  not  far 
from  25  per  cent  for  average  conditions.  Thus  it  is  seen  that 
it  will  require  much  more  fuel  to  operate  a  12-horsepower 
engine  empty,  or  under  no  load,  than  to  operate  a  13^-horse- 
power  engine  under  full  load. 


FARM  MOTORS 


The  average  farm  well  will  not  furnish  water  faster  than 
it  could  be  pumped  with  a  small  13^-  or  two-horsepower 
engine;  so  a  larger  load  cannot  be  provided  by  increasing  the 
size  of  the  pump  or  the  number  of  strokes  per  minute.  The 
question  is  often  asked,  when 
the  purchase  of  an  engine 
for  pumping  is  contemplated, 
whether  it  would  not  be  best 
to  purchase  a  much  larger 
engine  than  actually  needed 
in  order  that  it  may  be  used 
for  other  work.  If  the  pump- 
ing is  to  be  continuous,  that 
is,  every  day,  it  will  be  found 
more  economical  to  buy  a 
small  engine  to  do  the  pump- 
ing and  a  comparatively 
larger  one  for  the  other  work. 
This  will  be  explained  by 
the  following  calculation: 

Fuel  per  year  for  13^horse- 
power  engine,  light  pumping  load, 
2  hours  per  day,  equals  0.2  gal- 
lons times  365,  or  73  gallons. 

Fuel  per  year  for  8-horse- 
power  engine,  light  pumping  load, 
2  hours  per  day,  equals  0.45  gal- 
lons times  365,  or  164.3  gallons. 

Difference  equals  164.3 — 73, 
or  91.3  gallons. 

At  15c  per  gallon,  91.3  times  15c  equals  $13.69. 

This  will  more  than  pay  for  the  interest  on  the  cost  of  the 
smaller  engine,  and  its  depreciation.     If  the  comparison  be 


233.      A    .special    type    of    engine 
used  for  pumping. 


364 


AGRICULTURAL  ENGINEERING 


made  with  a  larger  engine,  the  difference  in  the  cost  of  oper- 
ation would  be  greater. 

The  Tjrpe  of  Engine.  The  type  of  engine  to  select  will 
depend  largely  on  the  kind  of  service  required.  If  the  engine 
is  to  be  placed  upon  some  horse-propelled  machine,  like  the 
binder,  to  drive  the  machinery,  a  light-weight  engine  is 
highly  desirable.  Lightest  weight  may  be  secured  by  select- 
ing a  high-speed  two-stroke  cycle  engine.    The  four-stroke 


Fis.    234.     A  gasoline  engine  used  to   operate   the  machinery  of  a  grain 

binder. 


cycle  may  be  made  quite  light  by  introducing  high  rotative 
speed  and  using  refinement  in  construction.  Usually,  high 
speed  is  conducive  to  increased  wear  and  short  life.  Modern 
automobile  design  has,  by  improved  methods  and  materials 
of  construction,  practically  overcome  the  objections  to  the 
high-speed  engine. 


FARM  MOTORS  365 

The  average  farm  machine  does  not  require  an  extremely 
steady  power,  and  for  this  reason  the  hit-or-miss  governed 
engine  is  the  most  satisfactory  for  average  conditions,  on 
account  of  its  simphcity  and  economy.  Where  an  engine  is 
used  for  electric  Hghting,  the  throttle-governed  engine  or  an 
engine  with  extra-heavy  fly  wheels  should  be  used. 

The  Mounting.  The  stationary  engine  has  many  advan- 
tages over  the  portable  engine  in  that  it  can  be  better  pro- 
tected and,  when  mounted  upon  a  good  foundation,  can  per- 
form its  work  under  the  best  conditions  satisfactorily.  The 
pumping  engine  should  be  a  stationary  engine;  it  may  also 
perform  such  other  work  as  may  be  brought  to  it.  It  ^vill 
prove  highly  satisfactory  to  locate  the  pump  house,  the  farm 
shop,  and  the  milk  house  so  as  to  enable  the  power  from  one 
engine  to  be  used  in  all. 

The  Quality.  A  poorly  constructed  and  inadequately 
equipped  engine  is  a  bad  investment  at  any  cost.  A  gasohne 
engine  should  not  only  run  and  furnish  power  for  a  time,  but 
it  should  be  so  constructed  and  of  such  material  as  to  have  a 
long  hfe  and  require  the  minimum  amount  of  attention  and 
repair.  In  considering  the  purchase  of  an  engine,  cognizance 
should  be  given  to  the  chief  factor  which  causes  the  manu- 
facturer to  build  a  high-grade  engine, — namely,  the  desire  to 
earn  a  reputation  for  building  first-class  goods. 

The  vital  parts  of  a  gasoline  engine,  as  of  any  machine, 
are  those  which  wear  and  which  must  be  adjusted  and 
repaired.  The  following  points  are  important:  First,  these 
parts  should  be  provided  with  adequate  lubrication,  as  it  is 
the  principal  factor  in  reducing  wear.  Second,  the  size  of  the 
parts  that  wear  should  be  of  liberal  dimensions  and  of  a  good 
quality  of  material.  Third,  the  parts  should  be  easily 
adjusted.  Fourth,  the  parts  should  be  easily  replaced  when 
worn  out. 


366  AGRICULTURAL  ENGINEERING 

Testing.  A  brake  test  may  be  made  of  the  engine  to 
determine  the  amount  of  power  it  will  deliver  and  the  amount 
of  fuel  required  per  horsepower  per  hour.     In  addition  to 


Fig.  235.     A   gasoline  engine  arranged  for  a  test.     The  brake  Is  on  the 

back  side. 

determining  the  power  of  the  engine,  if  the  test  be  continued 
for  a  time  (two  hours  or  longer)  an  examination  may 
be  made  of  the  efficiency  of  the  cooHng  system  and  of  the 


FARM  MOTORS  367 

ability  of  the  engine  to  carry  a  full  load  without  any  over- 
heating of  the  bearings,  or  other  disorders. 

Estimating  Horsepower.  The  horsepower  of  a  gasoline 
engine  may  be  estimated  from  the  diameter  of  the  cylinder, 
the  length  of  stroke,  and  the  revolutions  per  minute.  If  these 
quantities  are  known  for  several  engines,  a  comparison  of  their 
horsepower  may  be  made.  Such  an  estimate  can  only  be 
considered  approximate,  however. 

A  satisfactory  formula  for  estimating  the  horsepower  of 
gasoUne  engines  of  the  four-stroke  cycle  type  is  as  follows : 

D2  L  R* 
B.H.P.  =  

18,000 
where  D  =  diameter  of  cylinder  in  inches. 
L  =  length  of  stroke  in  inches. 
R   =   revolutians  per  minute. 

For  two-stroke  cycle  engines  the  formula  should  read  as 
follows : 

D«LR 

B.H.P.= 

13,600 

Another  formula  which  has  been  suggested  for  vertical 
tractor  engines  is: 

66  D2  L  Rf 
B.H.P.  = 


1,000,000 
For  horizontal  engines  the  formula  is  made  to  read  as 
follows : 

75  D2  L  R 

B.H.P.  = 

1,000,000 

These  formulas  will  agree  very  closely  with  the  brake 
horsepower  of  tractor  engines  developed  in  public  test. 


*E.  W.  Roberts. 
tW.  F.  MacGregor. 


368  AGRICULTURAL  ENGINEERING 

In  selecting  an  engine,  the  accessories  are  often  given  little 
attention,  when  they  should  be  carefully  inspected;  and, if 
the  engine  is  not  well  equipped  in  the  way  of  first-class  acces- 
sories, they  should  be  selected. 

The  lubricating  system  should  be  permanently  installed 
and  so  arranged  as  to  give  all  working  parts  a  liberal  supply  of 
oil.  The  multiple  oil  pump  is  to  be  highly  commended  in 
this  connection.  Exposed  oil  holes,  which  may  become  filled 
with  dirt  and  grit,  should  be  guarded  against. 

Summary.  The  following  outline  is  suggested  to  aid  a 
purchaser  in  making  a  comparison  of  the  merits  and  value  of 
different  engines.  The  information  asked  for  in  this  outline 
should  be  so  obtained  from  all  the  engines  considered. 

Things  to  Consider  in  Selecting  an  Engine. 

Name  of  engine. 

Type — stationary  or  portable. 

Rated  horsepower. 

Diameter  of  cylinder. 

Length  of  stroke. 

Revolutions  per  minute. 

Piston  speed  per  minute. 

Calculated  horsepower  by  formula. 

Cooling  system. 

Frame — construction. 

Main  bearings — construction,  accessibility,  and  adjustment. 

Cylinder   and   piston — construction. 

Crank — construction. 

Gears — construction. 

Valves — construction  and  accessibility. 

Ignition  system — construction  and  protection. 

Lubrication  system — construction  and  completeness. 

QUESTIONS 

1.  What  are  the  principal  features  to  be  considered  in  selecting 
a  gasoline  or  oil  engine? 


FARM  MOTORS  369 

2.  What  will  determine  the  size  to  be  selected? 

3.  Why  is  it  not  economy  to  use  a  large  engine  for  light  work? 

4.  How  much  power  is  usually  required  to  operate  a  farm  pump? 
A  chum?  A  washing  machine?  A  feed  mill?  A  com  sheller?  An 
ensilage  cutter?    A  threshing  machine? 

5.  What  should  govern  the  type  of  engine  to  be  selected? 

6.  Where  may  a  portable  engine  be  used  to  advantage? 

7.  What  are  some  of  the  indications  of  quahty  in  a  gasoline  or  oil 
engine? 

8.  Of  what  use  would  a  test  of  the  horsepower  be? 

9.  Explain  how  the  horsepower  of  an  engine  can  be   estimated. 

10.  A  four-stroke  cycle  engine  has  a  cylinder  8  inches  in  diameter; 
the  stroke  is  10  inches  long  and  it  operates  at  360  revolutions  per  min- 
ute.    Estimate  its  horsepower. 

11.  What  are  some  features  to  consider  in  selecting  the  accessories 
of  an  engine? 

12.  Give  a  list  of  the  parts  that  should  be  inspected  in  selecting  a 
gasoline  or  oil  engine. 

Note  : — The  instructor  here  should  furnish  the  students  with  problems 
in  the  estimating  of  the  horsepower  of  engines,  perhaps  measuring 
certain  engines  and  comparing  the  estimated  horsepower  with  manu- 
facturer's rating. 


CHAPTER  LVIII 
THE  GAS  TRACTOR 

The  Utility  of  the  Gas  Tractor.  The  gas  tractor — and 
reference  is  here  made  to  the  tractor  with  the  internal-com- 
bustion engine — has  developed  faster  dm*ing  the  past  ten 
years  than  has  any  other  machine  used  on  the  farm.  On  the 
broad  prairies,  where  the  conditions  are  the  most  favorable 
for  its  use,  it  is  rapidly  taking  first  place  over  the  horse;  and  in 
less  favorable  locahties,  where  intertilled  crops  are  grown, 
the  gas  tractor  is  being  successfully  tried  out.     All  this  has 


Fig.    23C. 


A    fcmall    gas    tractor    plowing.      It   may    be    successfully 
operated  by  one  man. 


taken  place  despite  the  fact  that  ten  years  ago  the  gas  tractor 
was  an  unusual  sight.  No  one  reason  can  be  given  for  this 
increase  in  power  farming.  The  new  broad  open  fields  of  the 
West,  the  rapid  development  of  the  internal-combustion 


370 


FARM  MOTORS 


371 


engine,  and  especially  the  factor  of  economy,  are  suggestive 
causes. 

The  tractor  has  been  regarded  as  unwieldy  in  small  fields, 
but  this  difficulty  has  been  largely  overcome  by  using  the 
proper  system  in  laying  out  the  lands.  One  convenient  sys- 
tem is  to  lay  out  the  fields  in  lands  of  such  widths  as  to  lose 
Httle  time  in  turning  at  the  ends.  A  strip  is  left  at  each  side 
of  the  field  of  a  width  equal  to  the  turning  strip  at  the  ends, 
and  sides  and  ends  are  turned  last  by  plowing  around  the 
entire  field. 

The  tractor  was  first  introduced  for  plowing,  as  this 
requires  more  power  than  any  other  kind  of  farm  work ;  but  it 
is  also  now  being  generally  used  in  seeding  and  harvesting. 
In  many  instances  several 
of  these  operations  are 
carried  on  at  the  same 
time. 

A  gas  tractor  consists 
of  an  engine,  the  transmis- 
sion, and  the  truck.  These 
parts  will  now  be  discussed 
under  separate  heads. 

The  Engine.  The  trac- 
tor engine  does  not  differ 
materially  from  any  other 
internal -combustion  en- 
gine. No  one  type  of  engine  has  been  generally  adopted 
for  traction  purposes.  However,  nearly  all  are  of  the  four- 
stroke  cycle  type.  The  differences  in  these  motors  lie  in  the 
number  of  cylinders,  the  speed  of  the  engine,  and  the  method 
of  governing. 

The  single-cylinder  engine  has  a  decided  advantage  in 
simplicity.     It  is  easier  to  manage  a  one-cylinder  than  a  two- 


Fig.  237. 


The  motor  of  an   oil-burning 
tractor. 


372  AGRICULTURAL  ENGINEERING 

cylinder  engine.  If  the  engine  is  not  in  proper  adjustment 
there  is  no  tendency  to  continue  to  operate  it,  as  there  is  when 
there  are  two  or  more  cyhnders,  letting  the  remaining  ones 
furnish  more  than  their  share  of  the  power.  A  multi- 
plicity of  cylinders,  on  the  other  hand,  for  a  given  power, 
reduces  the  magnitude  of  the  impulses  and  thus  to  a  large 
extent  relieves  the  gearing  of  severe  shocks.  The  multiple- 
cylinder  engine  furnishes  a  steady  power  and  is  a  little  more 
agreeable  to  operate  for  that  reason.  There  seems  to  be 
little  doubt  but  that  greater  skill  is  required  to  keep  the  com- 
plicated engine  in  proper  adjustment  and 
repair. 

The  Clutch.  As  the  gas  engine  cannot 
be  started  under  load,  it  is  necessary  to 
have  a  clutch  to  engage  the  engine  with 
gears  or  with  chains  and  sprockets  that 
transmit  the  power  to  the  drivers.     This 

Fig,  238.  One  form       i     .    i      •  n  i   ,  n 

of  clutch.  The  wood-  clutch  IS  generally  used  to  engage  a  pulley 

en   shoes    are    force;!         ,  . ,  •  .  i   j.        i    •  j.     i  • 

outward  against  the  whcu  the  cugmc  IS  uscd  to  drivc  a  station- 
ellSagtng  ^'t'^by^fSc^-  ary  machiuc  with  a  belt,  when  the  traction 
****"■  gearing  is  disengaged. 

In  construction,  the  clutch  consists  of  shoes  usually  made 
of  wooden  blocks,  which,  by  suitable  levers,  are  made  to  bear 
against  a  disk  or  other  surface  with  sufficient  pressure  to 
cause  the  power  to  be  transmitted  through  the  parts  in 
contact.  The  form  and  material  of  the  friction  surfaces 
vary  widely.  Sometimes  the  clutch  takes  the  form  of  two 
cones,  hence  the  name  cone  clutch.  Again,  the  friction 
may  take  place  between  a  series  of  disks,  one-half  of  which  are 
attached  to  the  engine  shaft  and  the  other  half  to  the  trans- 
mission. This  type  of  clutch  is  called  a  multiple-disk  clutch, 
and  the  disks  are  usually  engaged  by  the  pressure  of  a  spring 
which  may  be  brought  to  bear  at  the  most  suitable  time. 


FARM  MOTORS  373 

The  clutch  is  a  vital  part  of  the  tractor  and  should  be 
located  as  close  to  the  engine  as  possible.  The  higher  the 
speed  at  which  the  clutch  rotates  the  smaller  force  it  will  have 
to  transmit. 

The  Gearing.  The  gears  are  an  important  part  of  the 
tractor.  They  should  (1)  be  of  Uberal  dimensions  and  of 
great  strength;  (2)  be  constructed  of  such  materials  as  to 
resist  wear  to  the  greatest  advantage;  (3)  be  adequately  lubri- 
cated and  protected  from  dirt  and  grit. 

Change  of  Speed.  Change  of  speed  is  especially  desirable 
with  light  tractors  and  is  quite  necessary  where  the  land  is 
rolling.  The  load  which  any  tractor  will  draw  is  limited  by 
the  load  it  is  able  to  draw  up  the  steepest  incline.  If  a 
reduction  of  speed  be  made  for  incUnes  or  hills  a  larger  load 
may  be  carried  continuously. 

A  reverse  in  direction  of  travel  or  a  change  of  speed  is 
accomplished  in  two  general  ways :  by  sliding  gears,  which  is 
the  accepted  method  now  used  in  automobiles;  and  by  plane- 
tary gears.  The  former  is  the  simpler  method  but  is  not  so 
convenient  of  operation. 
Planetary  gears  take 
their  name  from  the 
gears,  being  fitted  to  a  re- 
volving frame  or  spider.    | 

The  Trucks.    One  of 

,,  ,  .  ,        ,  .  I'i^  tni(k    for   a   ga.8    tractor, 

the  most  important  parts     phowiun    ii.xi...,    gearing,   and  steering  and 

of  the  modem  tractor  is   ^'■*"*"^  "*^^''^- 

the  truck,  which  consists  of  the  frame  and  the  steering  and 
drive  wheels.  The  frame  is  the  backbone  of  the  tractor, 
and  to  it  are  attached  the  bearings  that  carry  the  main  axle 
and  the  shafts  which  support  the  gears. 

The  Steering  Wheels.  Two  methods  of  constructing  the 
axle  of  the  steering  wheels  are  in  common  use.     In  one  the 


374  AGRICULTURAL  ENGINEERING 

axle  is  pivoted  at  the  center,  and  steering  is  accomplished  by 
revolving  the  axle  about  this  pivot  or  king  bolt.  The  main 
advantage  of  this  system  is  that  the  steering  wheels  may  be 
turned  while  the  tractor  stands  still. 

In  the  other  style  the  axle  is  pivoted  just  inside  of  each 
steering  wheel  and  each  wheel  is  turned  about  its  own  pivot. 
This  style  of  steering  mechanism  is  easy  to  handle  while  in 
motion.  It  is  quite  positive,  that  is,  there  is  no  slack  to  take 
up  in  the  chains,  and  it  is  of  more  rapid  action  than  the  other 
style. 

The  Traction  Wheels.  The  traction  wheels  should  be 
carefully  considered  in  making  a  selection  of  a  tractor,  because 
certain  wheels  are  adapted  to  certain  conditions.  If  the 
ground  over  which  the  tractor  must  pass  be  soft,  it  is  highly 
desirable  that  both  the  drive  and  the  steering  wheels  be  as 
high  as  practical.  Wheels  of  large  diameter  present  a  larger 
section  of  their  periphery  to  the  surface  of  the  ground,  and 
so  cut  in  but  slightly.  Extensions  are  provided  by  all  manu- 
facturers for  making  the  drive  wheels  wider  for  work  in 
soft  ground.  Where  the  soil  is  exceedingly  soft,  the  cater- 
pillar tread  or  creeping  grip  should  be  used.  It  is  possible  to 
use  this  type  of  tractor  in  marsh  or  swamp  soils  or  over  sand 
where  it  is  impractical  to  use  horses. 

The  Equipment.  Too  much  emphasis  cannot  be  laid  upon 
the  importance  of  securing  a  tractor  which  is  well  equipped. 
Often  there  is  a  serious  loss  of  time  resulting  from  the  poor 
quality  of  parts  that  cost  but  a  few  cents.  A  purchaser 
should  see  that  the  tractor  has  modern  high-class  ignition, 
carburation,  and  lubrication  systems. 

QUESTIONS 

1.  What  are  some  of  the  conditions  under  which  the  gas  tractor 
can  be  used  with  economy? 


FARM  MOTORS  375 

2.  To  what  kinds  of  work  is  the  present  gas  tractor  adapted? 

3.  What  are  some  of  the  advantages  and  disadvantages  of  the 
multiple-cylinder  engine  for  a  tractor? 

4.  Why  is  the  clutch  an  important  part  of  the  gas  tractor? 

5.  Describe  the  differences  in  the  shoe,  cone,   and  multiple-disk 
clutches. 

6.  Why  is  the  gearing  an  important  part  of  a  gas  tractor? 

7.  How  may  a  change  of  speed  be  accomplished? 

8.  What  is  the  purpose  of  the  frame? 

9.  Describe  two  styles  of  steering  wheels. 

10.  Discuss  the  construction  of  traction  wheels. 

11.  Why  should  the  equipment  of  the  tractor  be  given  careful  con- 
sideration? 


CHAPTER  LIX 
THE  STEAM  BOH^ER 

The  Steam  Power  Plant.  A  steam  power  plant  consists 
essentially  of  two  parts,  the  steam  boiler,  for  generating  steam 
by  the  combustion  of  fuel;  and  the  steam  engine,  which  con- 
verts into  work  the  energy  contained  in  the  steam.  It  is 
customary,  however,  to  refer  to  the  entire  steam  plant  as  the 
steam  engine,  when  the  plant  is  small.  When  the  boiler  and 
engine  are  mounted  on  wheels  and  arranged  with  suitable 
gearing  for  propelling  itself  as  well  as  for  drawing  loads,  the 
outfit  is  referred  to  as  a  traction  engine.  Of  late  years  it 
has  become  customary  to  refer  to  the  steam  traction  engine  as 
the  steam  tractor.  The  subj  ect  of  the  steam  power  plant  will 
be  divided  into  three  parts,  confined  to  as  many  chapters,  as 
follows:  the  steam  boiler,  the  steam  engine,  and  the  steam 
tractor.  At  one  time  the  steam  engine  as  defined  above  and 
the  steam  tractor  were  the  principal  sources  of  power  for 
agricultural  purposes,  when  large  units  were  required.  The 
development  of  the  internal-combustion  engine  and  tractor 
has  been  more  rapid  in  recent  years  than  that  of  the  steam 
engine  and  tractor. 

The  Principle  of  the  Steam  Engine.  The  steam  engine  is 
a  heat  engine,  in  that  its  function  is  to  transfer  the  heat  pro- 
duced by  the  combustion  of  fuel,  usually  wood  or  coal,  into 
mechanical  energy.  It  might  be  styled  an  external-combus- 
tion engine,  in  that  combustion  takes  place  outside  of  the 
boiler  proper  and  the  heat  is  absorbed  by  passing  the  hot 
gases  through  tubes  surrounded  by  water, 

376 


FARM  MOTORS  377 

In  an  open  vessel  water  cannot  be  heated  above  the  boil- 
ing point  of  212°  F.,  but  heat  continues  to  be  absorbed  and  is 
used  in  the  formation  of  vapor.  Water  under  pressure  boils 
at  a  higher  temperature.  Thus  if  the  pressure  inside  the  con- 
taining vessel  were  two  pounds  greater  than  atmospheric 
pressure,  the  boiling  point  would  be  about  228°  F.  Changing 
water  into  vapor  increases  its  volume  many  fold.  At  atmos- 
pheric pressure  the  volume  of  the  vapor  is  about  1700  times 
that  of  the  liquid.  At  100  pounds  pressure  the  volume  of 
the  steam  is  about  240  times  the  volume  of  the  liquid.  Water 
vapor,  or  steam,  is  a  colorless  gas  which  obeys  all  of  the  laws 
of  gases  as  far  as  expansion  and  change  of  temperature  are 
concerned. 

Functions  of  a  Boiler.  The  functions  of  a  boiler  are  to 
absorb  heat  from  the  hot  gases  produced  by  the  burning  cf 
fuel  and  to  transmit  it  to  the  water  contained  within,  causing 
it  to  vaporize  into  steam.  The  steam  boilers  used  in  agricul- 
tural plants  and  in  traction  engine  service  include  the  firebox, 
or  furnace,  which  may  be  placed  either  directly  underneath 
the  main  part  of  the  boiler  or  entirely  within  it. 

Location  of  the  Furnace.  Boilers  with  the  fire  box  out- 
side of  the  boiler  proper  are  called  externally-fired  boilers. 
This  type  can  safely  be  used  for  stationary  work  and  are 
usually  set  in  brick  work,  which  forms  a  large  part  of  the 
furnace.  Those  which  have  the  furnace  within  the  main 
body  of  the  boiler,  or  shell,  as  it  is  called,  are  said  to  be  inter- 
nally-fired boilers.  Most  of  the  boilers  used  in  agricultural 
practice  and  all  of  the  boilers  used  for  traction  engine  service 
are  internally  fired. 

The  Vertical  Boiler.  The  vertical  boiler  is  used  in  small 
units  and  where  space  is  especially  valuable.  It  consists  of 
a  cyhndrical  shell  containing  a  furnace  in  the  lower  end,  over 
which  is  placed  a  tube  sheet  or  plate  and  a  system  of  tubes. 


378 


AGRICULTURAL  ENGINEERING 


These  boilers  are  not  regarded  as  very  durable  and  are  quite 

difficult  to  clean  properly. 

The  Locomotive  Type  of  Boiler.  The  locomotive  type  of 
boiler  is  the  one  most  generally  used  for  trac- 
tion engine  service.  It  consists  of  a  fire  box 
made  of  steel  plates,  in  which  the  furnace  is 
placed;  a  cyhndrical  shell  extending  forward, 
containing  a  comparatively  large  number  of 
tubes;  a  smoke  box  at  the  front  end;  and  a 
stack  to  carry  the  smoke  away. 

The  fire  box  is  almost  entirely  surround- 
ed with  water.     The  plate  directly  above  the 

vertical  boiler,  fire  is  Called  the  crown  sheet  and  the  plates 

valve;   'b,  try  forming  the  sides  of  the  box  are  called  side 

cocks*      c7     iniGC" 

tor;  'd,  'hand  sheets.  lu  some  instances  fire  boxes  are  so 
gauge;  'f,  gauge  made  as  to  have  water  beneath  the  grates; 
doorrn,  'as^h  such  a  boiler  is  said  to  have  a  water  bottom. 
^^^^'  The  boiler  has  a  cylindrical  chamber  riveted 

to  the  top  of  the  shell,  in  which  the  steam  collects  and  from 
which  it  is  drawn  to  the  engine.  This  part  is  called  the 
steam  dome,  and  is  a  device  for  drying  the  steam. 

All  parts  of  the  boiler  are  made  of  the  best  steel  plates,  and 
the  seams  are  carefully  riveted  together.     The  joints  are  made 


Fig.        240. 


Fig.  241.     A  boiler  of  the   locomotive  type  In  section:    A,  steam  dome; 
B,  smoke  box;    C,   fire  box;    D,   grates;    E,   tubes;    F,  crown   sheet. 


FARM  MOTORS  379 

tight  by  calking  or  battering  the  edges  of  the  seams  do-wn 
with  a  special  tool  designed  for  the  purpose.  The  flat  plates  of 
the  fire  box  are  supported  by  bolts  or  studs  running  from  one 
plate  to  the  other.  These  are  called  stay  bolts,  except  those 
over  the  crown  sheet,  which  are  called  crown  bolts.  The 
boiler  is  usually  provided  with  a  valve  at  the  lowest  point, 
which  may  be  opened  to  allow  any  sediment  in  the  boiler  to 
be  blown  out. 

In  the  management  of  the  locomotive  type  of  boiler,  great 
care  should  be  taken  to  keep  the  water  over  the  crown  sheet 
at  all  times. 

Retum-Flue  Boilers.  The  return-flue  boiler  has  a  large 
cyhndrical  shell  in  which  a  comparatively  large  flue  is  placed, 

crate  surface  which  can  ^'S-  242.  a  sectional  view  of  a  retum- 
*^  flue  boiler. 

be  provided.     This  type, 

however,  is  regarded  as  one  of  the  safest,  and  is  very  eco- 
nomical in  the  consumption  of  fuel. 

Capacity  of  Boilers.  The  capacity  of  a  boiler  is  usually 
designated  in  horsepower.  Formerly  this  meant  the  capacity 
to  supply  enough  steam  for  an  engine  of  the  designated 
horsepower.  Now  boiler  horsepower  means  the  capacity 
to  absorb  a  certain  amount  of  heat  in  a  given  time.  The 
standard  horsepower  as  established  in  this  country  is  the 
capacity  to  evaporate  30  lbs.  of  water  per  hour  into  steam  at 


380  AGRICULTURAL  ENGINEERING 

70  lbs.  pressure  by  the  gauge  from  the  feed  water  at  a  temper- 
ature of  100°  F. 

It  is  easy  to  see,  however,  that  the  capacity  of  any  boiler 
depends  on  its  ability  to  burn  fuel,  or  the  area  of  the  grate 
surface,  and  on  the  heating  surface  which  will  absorb  the  heat 
produced.  Thus  it  is  possible  to  estimate  the  capacity  of  the 
steam  boiler  from  the  size  of  the  grates,  allowing  from  3^  to  3/^ 
square  foot  for  each  horsepower.  In  hke  manner  the  horse- 
power may  be  calculated  by  determining  the  entire  heating 
surface  of  the  boiler,  or  the  area  of  the  plates  and  tubes  which 
have  heated  gases  on  one  side  and  water  on  the  other,  and 
allowing  14  square  feet  of  heating  surface  for  each  horsepower. 

Quality  of  Steam.  As  steam  leaves  the  boiler  there  is  a 
tendency  for  it  to  carry  water  with  it  in  the  form  of  spray. 
It  is  the  purpose  of  the  steam  dome  to  cause  the  water  to 
settle  from  the  steam  as  fast  as  possible.  Steam  which  con- 
tains water  in  the  form  of  spray  is  called  wet  steam,  and  the 
proportion  of  water  to  steam  is  sometimes  called  the  quality 
of  steam.  Steam  which  does  not  contain  any  water  is  said 
to  be  dry  steam.  When  dry  steam  is  passed  through  highly 
heated  tubes  it  is  heated  above  the  boiling  point  of  water  for 
the  pressure  under  which  the  steam  is  confined.  When  in 
this  condition  the  steam  is  said  to  be  superheated.  Some 
boilers  are  provided  with  superheaters  for  raising  the  tem- 
perature of  the  steam  in  this  way.  To  prevent  the  loss  of 
heat  it  is  customary  to  cover  the  pipes  leading  the  steam  from 
the  boiler  to  the  engine  with  some  non-conductive  material  in 
the  shape  of  pipe  covering. 

Boiler  Accessories.  All  boilers  must  be  provided  with 
certain  accessories,  in  order  to  permit  of  their  successful 
operation  and  management. 

Gauge  Cocks.  Boilers  are  usually  provided  with  two  or 
three  gauge  cocks  to  enable  the  fireman  to  determine  the 


FARM  MOTORS  381 

height  of  the  water  within  the  boiler.  If  the  gauge  cock 
below  the  surface  of  the  water  be  opened,  a  cloud  of  white 
vapor  will  be  emitted;  if  the  cock  in  connection  with  the  steam 
space  be  opened,  a  colorless  gas  will  escape.  In  this  way 
the  height  of  the  hquid  may  be  determined  at  any  time.  It 
is  customary  to  put  the  lower  gauge  cock  sUghtly  above  the 
level  of  the  crown  sheet  or  upper  tubes. 

The  Gauge  Glass.  In  addition  to  the  gauge  cocks,  the 
gauge  glass  is  provided,  which  shows  directly  the  height  of 
the  water  in  the  boiler.  Care  should  be  taken  to  see  that  the 
gauge  glass  does  not  become  clogged  with  sediment  and  thus 
fail  in  accuracy.  The  low  water  condition  is  reached  when 
the  water  does  not  cover  the  heated  plates  of  the  boiler. 
Steam  is  not  a  good  conductor  of  heat;  so  if  the  plates  become 
uncovered  they  are  quite  sure  to  become  so  hot  as  to  be 
softened  and  perhaps  destroyed  by  the  pressure  of  the  steam. 
Low  water  is  one  of  the  common  causes  of  boiler  explosions. 

The  Pressure  Gauge.  Another  essential  accessory  for  the 
steam  boiler  is  the  pressure  gauge.  This  instrument  indicates 
the  pressure  of  the  steam  within  the  boiler  in  pounds  per 
square  inch.  The  usual  pressure  gauge  consists  of  a  hollow 
brass  tube  curved  to  a  circle,  which  tends  to  straighten  as  the 
pressure  within  increases.  By  connecting  this  tube  with  a 
needle  over  a  graduated  dial,  by  suitable  mechanism,  the 
pressure  may  be  indicated  directly.  A  siphon  directly  below 
the  gauge  prevents  steam  from  entering  and  heating  the  tube 
and  changing  its  elasticity. 

The  Safety  Valve.  Every  boiler  should  be  provided  with 
a  safety  valve,  which  will  permit  the  escape  of  the  steam  as 
fast  as  generated,  after  a  certain  pressure  has  been  reached, 
in  order  that  the  pressure  shall  not  exceed  the  strength  of  the 
boiler.  The  usual  safety  valve  is  held  closed  by  a  spring 
which  may  be  adjusted  for  the  desired  pressure.     Care  should 


3S2 


AGRICULTURAL  ENGINEERING 


Fig.     243.      A     spring- 
loaded  safety  valve. 


be  taken  to  see  that  the  pressure  valve  is  kept  in  working 
order,  and  that  it  is  not  set  too  high  for  the  strength  of  the 
boiler.  It  should  also  have  sufficient  capacity  to  release  the 
steam  as  fast  as  it  can  be  produced  in 
the  boiler  under  any  condition. 

The  Fusible  Plug.  As  an  additional 
safety  device,  a  fusible  plug,  containing 
a  core  made  of  some  metal  with  a  low 
melting  point,  hke  tin,  is  placed  at  the 
highest  point  of  the  crown  sheet  which 
will  be  first  exposed  by  low  water.  When, 
because  of  low  water,  the  plate  becomes  heated,  the  soft 
metal  core  of  the  plug  melts  away,  causing  the  steam  to  blow 
on  the  fire  and  put  it  out. 

The  Boiler  Feeder.  In  order  to  re- 
ceive additional  water  the  boiler  must  be 
provided  with  some  sort  of  feeder.  One 
such  device  is  the  crosshead  pump,  which 
is  attached  directly  to  the  crosshead  of 
the  engine  and  can  be  operated  only  when 
the  engine  is  running.  The  independent  pump  has  a  steam 
cylinder  of  its  own  and  may  be  operated  by  steam  from  the 
boiler.  This  type  of  pump  is  practically  a  small  steam  engine. 

Another  form  of  boiler  feeder  is 
the  injector y  which  takes  steam 
from  the  boiler  and,  by  allowing 
it  to  expand,  converts  its  energy 
into  kinetic  energy.  As  this  steam 
strikes  a  supply  of  cold  water 
within  the  injector  it  condenses, 
but  the  impact  drives  the  water 
into  the  boiler. 
The  Feed  Water  Heater.  Many  boilers  are  provided  wi t  ti 
feea  water  heaters  which  use  the  exhaust  steam  from  the  engme 


Fig.    245. 


A    standard 
injector. 


type 


FARM  MOTORS 


383 


to  heat  the  water  as  it  is  forced  into  the  boiler.  The  heat 
thus  saved  may  amount  to  as  much  as  ten  to  fifteen  per  cent. 
Boiler  Management.  In  managing  the  boiler  care  should 
be  taken  to  see  that  the  flues  are  kept  free  of  soot,  in  order 
that  the  heated  gases  may  come  in  direct  contact  with  the 
metal,  and  that  the  boiler  is  kept  clear  of  incrustation  on 
the  inside.  Such  accumulations  do  not  have  the  heat-con- 
ducting properties  of  the  steel  and  result  in  a  serious  loss  of 
heat.  If  the  scaly  deposits  from  the  water  become  too  thick, 
the  heat  may  not  be  carried  away  from  the  plate  fast  enough 
to  prevent  it  from  becoming  overheated.  Thus  care  should 
be  taken  not  only  to  use  water  which  is  free  from  foreign  sub- 
stances, but  also  to  clean  the  boiler  frequently. 


Fig.  246.     A    feed  water  heater    in  which  the  water    is  heated  by  the 
exhaust  steam. 

Foaming  sometimes  occurs  in  a  boiler,  due  largely  to  the 
presence  of  dirt,  alkaU,  grease,  or  other  foreign  matter.  It 
causes  a  large  amount  of  water  to  be  carried  away  with  the 
steam,  and  prevents  the  engineer  from  determining  accu- 
rately the  true  level  of  the  water.  Great  care  should  be  taken 
in  managing  the  boiler  when  foaming  takes  place. 

Low  water  in  a  boiler  should  always  be  guarded  against; 
and  if  at  any  time  it  should  occur,  the  further  generation  of 
heat  should  be  stopped  and  the  boiler  allowed  to  cool.  It  is 
inadvisable  to  try  to  remove  the  fire,  as  it  is  quite  sure  *o 
increase  its  intensity.    The  best  procedure  is  to  cover  the 


384  AGRICULTURAL  ENGINEERING 

fire  with  ashes,  earth,  or  even  green  coal.  Do  not  try  to  feed 
more  water  into  the  boiler,  as  cold  water  is  quite  apt  to  crack 
the  hot  plates  and  the  great  amount  of  steam  suddenly  gen- 
erated may  cause  an  explosion.  The  steam  boiler  under 
pressure  contains  a  large  amount  of  energy,  and  a  boiler 
explosion  is  very  disastrous. 

QUESTIONS 

1.  What  are  the  essential  parts  of  a  steam  power-producing  plant? 

2.  Explain  how  heat  is  converted  into  power  by  the  steam  plant. 

3.  What  is  the  function  of  the  steam  boiler? 

4.  What  two  general  locations  may  be  given  to  a  furnace? 

5.  Describe  the  vertical  boiler  and  the  conditions  to  which  it  is 
adapted. 

6.  Describe  the  construction  of  the  locomotive  type  of  boiler. 

7.  What  is  meant  by  a  return-flue  boiler? 

8.  How  is  the  capacity  of  a  boiler  designated? 

9.  How  may  the  horsepower  of  a  boiler  be  estimated? 

10.  What  is  meant  by  ''quality  of  steam"? 

11.  What  is  the  use  of  gauge  cocks  and  the  gauge  glass? 

12.  What  is  the  purpose  of  the  pressure  gauge? 

13.  What  is  necessary  to  provide  a  boiler  with  a  safety  valve? 

14.  Describe  the  use  of  the  fusible  plug. 

15.  What  is  the  purpose  of  the  boiler  feeder? 

16.  What  is  the  use  of  the  feed  water-heater? 

17.  Describe  in  a  general  way  the  management  of  a  steam  boiler. 

18.  What  is  meant  by  ''foaming"? 

19.  What  should  be  done  in  case  of  "low  water"? 


CHAPTER  LX    . 
THE  STEAM  ENGINE 


Mounting.  Steam  engines  used  in  agricultural  work  are 
usually  mounted  directly  upon  the  boiler,  making  with  the 
boiler  a  complete  power  plant,  as  in  the  case  of  a  portable  or 
traction  engine.  An  engine  mounted  upon  a  masonry  foun- 
dation is  said  to  be  a  stationary  engine.  All  such  engines  do 
not  differ  essentially  in  construction. 

Principle.  The  steam  engine  consists  fundamentally  of 
a  cylinder  containing  a  close-fitting  piston.  This  piston  is 
connected  through  a  piston  rod  to  a  crosshead  and  in  turn 
through  a  connecting  rod  to  a  crank  on  the  engine  shaft.  The 
crosshead  is  operated  between  guides.  The  steam  is  admit- 
ted at  the  ends  of  the  cyUnder  through  valves  contained 
within  the  steam  chest.  The  proper 
action  is  given  to  the  valves  by  an 
eccentric  on  the  engine  shaft,  con- 
nected either  to  the  valve  rod,  which 
extends  into  the  steam  chest  in  the 
case  of  a  nonreversing  engine,  or  to 
the  reversing  mechanism  on  a  revers- 
ing engine.  As  steam  enters  the 
cylinder  it  pushes  on  the  piston  and 
causes  it  to  move.  After  the  piston 
has  completed  a  part  of  the  stroke,  the  valve  closes,  but  the 
expanding  pressure  of  the  steam  in  the  cylinder  enables  it  to 
perform  additional  work  on  the  piston.  At  the  end  of  the 
stroke  the  steam  is  released,  and  the  pressure  is  applied  to  the 
opposite  side  of  the  piston.    This  is  all  done  automatically 

-3—  385 


Fip.  247.  A  sectional  view 
of  the  cylinder  and  steam 
chest  of  a  simple  engine. 


886 


AGRICULTURAL  ENGINEERING 


by  the  valve  mechanism,  or  valve  gear,  as  it  is  called.  The 
piston  is  fitted  with  rings  which  expand  against  the  walls  of 
the  cylinder,  making  a  gas-tight  fit.  The  power  developed 
by  the  engine  is  proportional  to  the  travel  of  the  piston  in  one 
minute  and  the  average  pressure  of  the  steam  on  its  face. 

Compound  Engines.  The  compound  engine  has  two 
cyhnders.  The  steam  is  admitted  first  into  the  smaller  one 
and  allowed  to  expand  to  a  certain  pressure,  and  then  it  passes 
to  the  second,  where  it  expands  more  fully.  The  compound 
engine  enables  the  cylinders  to  be  maintained  at  more  nearly 


Fig. 


248.     A    sectional    view   of   the   cylinders   and    steam    chest   of 
a   compound   engine. 


the  temperature  of  the  steam.  As  steam  expands,  it  cools; 
and  when  fresh  steam  is  admitted  after  the  expansion  of  a 
cyhnderful,  some  of  it  condenses,  losing  part  of  its  power. 
Compound  engines  also  tend  to  equalize  the  pressure  of  the 
steam  on  the  piston  throughout  the  stroke,  giving  a  steadier 
motion  and  lowering  the  stress  upon  the  working  parts. 

The  Double  Engine.  Many  traction  engines  are  pro- 
vided with  two  cylinders,  making  a  double  engine.  The 
cranks  are  on  the  same  shaft,  but  are  located  at  an  angle  of 
90  degrees  with  each  other,  so  that  at  no  time  can  both  cranks 


FARM  MOTORS  387 

stop  in  line  with  the  connecting  rod,  or  be  on  dead  center,  in 
such  a  way  that  the  engine  cannot  be  started  by  the  applica- 
tion of  steam. 

The  two-cylinder  engines  give  a  steadier  motion  but  are  not 
usually  as  economical  in  the  use  of  steam  as  the  single- 
cylinder  engines,  and  are  more  expensive. 

The  Fly  Wheel.  All  steam  engines  and  especially  single- 
cyhnder  engines  must  be  provided  with  a  fly  wheel  to  carry 
the  engine  over  dead  center,  when  the  steam  cannot  act  effec- 
tively upon  the  piston.  It  is  customary  to  make  this  fly 
wheel  in  the  form  of  a  pulley,  from  which  the  belt 
may  be  run  to  other  machines  as  desired. 

The  Governor.  The  purpose  of  the  governor  is 
to  maintain  a  uniform  speed.  The  usual  construc- 
tion of  a  governor  is  similar  to  that  shown  in  the 
accompanying  illustration.  The  fly  balls  are 
thrown  outward  by  centrifugal  force  as  they  are 
rotated,  thus  gradually  closing  the  valve  through 
which  the  steam  must  pass.  Governors  may  be 
adjusted  for  different  speeds. 

Lubrication.  One  important  fea- 
ture of  the  operation  of  the  steam 
engine  is  the  lubrication  of  the  piston,  which 
is  usually  accomplished  by  admitting  oil  with 
the  steam.  The  two  devices  in  common  use 
for  feeding  the  oil  uniformly  are  the  oil  pump 
and  the  lubricator.  The  oil  piunp  is  driven 
by  the  engine  and  is  simply  a  small  pump 
sight-  feed  lubri-  couuectcd  with  a  Suitable  reservoir  for  the  oil. 
It  can  be  adjusted  to  feed  oil  at  any  specified 
rate.  The  best  kinds  have  a  sight-feed  device,  which  en- 
ables the  engineer  to  see  the  rate  at  which  the  pump  is  feed- 
ing the  oil. 


388  AGRICULTURAL  ENGINEERING 

The  lubricator  consists  of  a  tank  of  oil  connected  under- 
neath with  a  short  column  of  water.  The  excess  weight  of 
water  over  that  of  the  steam  when  apphed  at  the  bottom  of 
the  oil  reservoir  enables  the  oil  to  be  fed  through  a  small 
valve,  a  drop  at  a  time.  The  accompanying  illustration 
shows  the  construction  of  a  lubricator. 

QUESTIONS 

1.  How  is  the  farm  steam  engine  usually  mounted? 

2.  Explain  the  principle  of  the  steam  engine. 

3.  Describe  the  compound  engine,  and  what  advantage  does  it 
offer? 

4.  What  are  the  merits  of  a  double  engine? 

5.  Why  is  it  necessary  for  a  steam  engine  to  have  a  fly  wheel? 

6.  Describe  the  action  of  the  governor. 

7.  Describe  the  action  of  the  steam  engine  lubricator. 

8.  What  other  oiling  device  is  in  common  use? 


CHAPTER  LXI 
THE  STEAM  TRACTOR 

A  steam  boiler  and  engine  mounted  upon  skids  or  on  a 
truck  to  permit  them  to  be  moved  from  place  to  place  make 
what  is  called  a  portable  steam  engine.  If  an  engine  be  pro- 
vided with  means  of  ready  control  and  with  gearing  for  trans- 
mitting the  power  to  the  traction  wheels,  thus  enabling  it  to 
propel  itself  forward  over  the  ground  and  perhaps  pull  a  load 
after  it,  the  outfit  is  called  a  steam  traction  engine^  or  a  steam 
tractor.    The  latter  term  has  come  into  use  recently. 

The  steam  boiler  and  the  steam  engine  have  been  dis- 
cussed under  separate  heads.  This  chapter  will  be  devoted 
to  a  discussion  of  the  features  of  the  steam  tractor  other  than 
the  boiler  and  the  engine. 

The  Moimting  of  the  Boiler.  There  are  two  general  types 
of  mounting  for  the  steam  tractor  boiler.  One  has  a  frame 
connecting  the  traction  and  steering  wheels  in  such  a  manner 
as  to  form  a  truck  sufficiently  strong  to  support  the  boiler. 
As  now  generally  manufactured  this  is  called  the  under- 
mounted  tractor,  but  a  general  name  for  this  style  of  construc- 
tion is  frame  mounted. 

Again,  the  boiler  may  be  used  as  the  frame  for  the  engine 
and  the  truck,  in  which  case  the  gearing  is  attached  to  the 
boiler  by  brackets  or  flanges  riveted  to  the  boiler.  This 
construction,  called  top  mounting,  is  in  more  general  use,  but 
is  criticised  by  some  because  the  boiler  is  subject  to  the 
stresses  produced  in  transmitting  the  power  from  the  engine 
to   the   traction  wheels.    When   the   traction  wheels   are 


390 


AGRICULTURAL  ENGINEERING 


mounted  on  brackets  attached  to  the  side  of  the  boiler,  the 
boiler  is  said  to  be  side-mounted. 

When  an  axle* is  provided  for  the  traction  wheels  and  it  is 
placed  to  the  rear  of  the  boiler,  it  is  said  to  be  rear -mounted. 
As  it  is  quite  impossible  to  keep  the  traction  wheels  in  the 
side-mounted  engine  perfectly  true,  the  rear-mounted  form 
is  generally  recognized  as  being  the  more  preferable  of  the  two. 
Any  wear  or  spring  at  the  outer  ends  of  the  axles  will  allow  the 


Fig.   251.     An    undermounted    double-cylinder    steam    tractor. 


wheels  to  approach  each  other  at  the  top  and  to  spread  at  the 
bottom,  thus  throwing  the  gearing  out  of  alignment. 

Some  rear-mounted  boilers  have  the  main  axle  mounted 
with  radius  arms,  that  the  boiler  may  be  carried  on  springs 
and  still  permit  the  gearing  to  be  in  proper  mesh  at  all  times. 

The  Mounting  of  the  Engine.  The  usual  method  of 
mounting  the  engine  is  to  attach  it  to  brackets  or  flanges 
riveted  to  the  top  of  the  boiler  proper.  This  construction  is 
generally  referred  to  as  top  mounting. 

As  previously  mentioned,  another  type  of  construction 
provides  a  frame  sufficiently  strong  to  carry  the  boiler  and 


FARM  MOTORS 


391 


engine.  In  this  case  the  engine  is  placed  underneath  the 
boiler,  and  is  styled  under- mounted.  This  construction 
relieves  the  boiler  of  all  stress  due  to  the  transmission  of 
power  and  places  the  engine  where  it  may  be  attended  by 
the  engineer  standing  on  the  ground. 

The  Steering  Wheels.  The  steering  wheels  of  the  steam 
tractor  engine  are  generally  mounted  on  an  axle  which 
may  be  turned  by  means  of  a  hand  wheel  and  a  worm  gear. 


Fig.   l'5l'.      a   top-mounted  steam  tractor. 

By  turning  the  hand  wheel  a  chain  attached  to  one  end  of  the 
axle  is  shortened,  while  another  at  the  other  end  is  lengthened. 
In  large  engines  the  power  for  steering  is  often  supplied  by  a 
separate  engine  or  is  derived  from  the  main  engine  by 
friction  clutches. 

The  Traction  Wheels.  The  traction  wheels  of  a  steam 
tractor  are  important  features  of  the  outfit  when  the  tractor 
is  to  be  used  for  drawing  loads  or  machines.  The  supporting 
power  of  the  wheels  depends  upon  the  diameter  of  the  wheel 


S92  AGRICULTURAL  ENGINEERING 

and  the  width  of  the  tire.  On  soft  ground,  it  is  customary  to 
provide  an  extra  width  of  tire  in  the  form  of  extensions,  which 
may  be  removed  when  not  needed. 

In  order  to  grip  the  surface  of  the  soil  sufficiently,  the 
traction  wheels  must  be  provided  with  cleats,  lugs,  grouters, 
or  spikes,  which  grip  the  soil  and  enable  the  tractor  to  exert  a 
greater  tractive  force.  The  form  of  these  lugs  should  be 
adapted  to  the  conditions  under  which  they  work. 

Rating.  The  size  or  capacity  of  the  steam  tractor  is 
designated  in  horsepower.  Formerly  it  was  customary  to 
indicate  its  tractive  power  in  terms  of  horses.  This  rating 
has  since  become  known  as  nominal  rating,  and  is  being 
superseded  largely  by  the  brake  horsepower  rating,  which 
indicates  the  most  practical  power  output  of  the  engine 
proper.  This  rating  is  ordinarily  about  three  times  the 
nominal  rating. 

'  A  large  part  of  the  power  of  the  engine  is  used  in  propelling 
the  tractor  and  in  overcoming  the  friction  of  the  gearing. 
The  tractive  efficiency  of  a  tractor  is  the  ratio  between  the 
power  delivered  at  the  draw  bar  and  the  power  furnished  by 
the  engine.  Ordinarily  this  is  about  50  per  cent,  but  on  soft 
ground  it  may  run  as  low  as  35  or  40  per  cent.  On  hard  roads 
it  may  be  much  higher  than  50  per  cent. 

Control.  The  control  of  the  steam  tractor  is  placed  (1)  in 
a  throttle,  through  which  the  admission  of  steam  to  the 
engine  is  controlled;  (2)  in  the  reverse,  which  controls  the 
direction  of  rotation  of  the  engine;  and  (3)  in  a  clutch  similar 
to  that  described  for  gas  tractors  which  connects  the  engine 
to  the  transmission.  Some  steam  tractors  have  a  brake  by 
which  the  tractor  may  be  held  in  place. 

The  Clutch.  The  clutch  on  a  steam  tractor  universally 
operates  within  the  fly  wheel  of  the  engine.     The  friction 


FARM  MOTORS  393 

shoes  used  are  made  of  wood,  and  are  forced  out  against  the 
rim  of  the  fly  wheel  by  suitable  hnkage. 

The  Differential.  In  order  to  permit  the  tractor  to  turn 
comers,  or  change  direction  a  mechanism  must  be  introduced 
which  will  allow  one  traction  wheel  to  travel  faster  than  the 
other.  This  mechanism  is  called  the  differential.  There  are 
two  types  of  differentials,  the  bevel  gear  and  the  planetary. 

The  Gearing.  The  gearing  of  a  steam  tractor  is  an 
important  part  of  the  outfit,  especially  when  the  tractor  is 
used  for  traction  purposes.  It  is  now  customary  to  make 
the  gears  very  ample  in  size  and  of  material  which  will  resist 
wear  to  the  greatest  extent  and  still  be  capable  of  resisting 
the  shocks  which  must  necessarily  come  upon  them.  Further- 
more, the  tractor  should  be  provided  with  means  of  excluding 
dust  and  grit  from  the  gears,  and  with  a  system  of  lubrication 
that  will  at  all  times  keep  the  gears  amply  lubricated. 

QUESTIONS 

1.  Discuss  the  different  types  of  boiler  mounting. 

2.  Explain  two  ways  of  mounting  the  engine. 

3.  In  what  two  ways  may  large  tractors  be  steered  by  power? 

4.  What  are  some  of  the  important  features  in  the  construction  of 
the  traction  wheels? 

5.  What  is  the  purpose  of  the  cleats  on  the  drive  wheels? 

6.  How  is  the  power  capacity  of  a  steam  tractor  designated? 

7.  How  is  a  steam  tractor  controlled? 

8.  What  is  the  purpose  of  the  differential  gearing? 

9.  Why  is  the  gearing  of  a  steam  tractor  worthy  of  careful  atten- 
tion? 

LIST  OF  REFERENCES 

Instructions  for  Traction  and  Stationary  Engineers,  William  Boss. 
Farm  Engines  and  How  to  Run  Them,  James  H.  Stephenson. 
Farm  Machinery  and  Farm  Motors,  J.  B.  Davidson  and  L.  W. 
Chase. 


894  AGRICULTURAL  ENGINEERING 

Power  and  the  Plow,  L.  W.  Ellis  and  Edward  A.  Rumley. 
Physics  of  Agriculture,  F.  H.  King. 
The  Gas  Engine,  F.  R.  Hutton. 
Gas  Engine  Principles,  Rodger  B.  Whitman. 
Farm  Gas  Engines,  H.  R.  Brate. 

The  Use  of  Alcohol  and  Gasoline  in  Farm  Engines.     U.  S.  Dept. 
of  Agr.     Farmers'  Bulletin  277. 


PART  SEVEN— FARM  STRUCTURES 


CHAPTER  LXII 
INTRODUCTION;  LOCATION  OF   FARM    BUILDINGS 

The  study  of  farm  buildings  is  important  to  those  engaged 
in  agricultural  pursuits,  for  the  following  reasons : 

1.  The  amount  of  capital  invested  in  farm  buildings  is 
large. 

2.  Convenient  farm  buildings  conserve  labor. 

3.  Comfortable  buildings  for  hve  stock  conserve  feed  and 
insure  maximum  production. 

4.  The  health  of  farm  animals  and  the  quality  of  the 
products  produced  by  them  depend  in  a  large  measure  upon 
the  sanitation,  ventilation,  and  lighting  of  the  farm  buildings. 

Capital  Invested  in  Farm  Buildings.  The  fixed  capital  of 
farms  is  divided  by  the  1910  Census  into  land,  buildings, 
implements,  machinery,  and  live  stock.  The  relative  impor- 
tance of  these  is  shown  by  the  percentage  which  each  bears  to 
the  whole. 

Land 69.5  per  cent 

Buildings 15.4  per  cent 

Live  stock 12.0  per  cent 

Implements  and  machinery 3.1  per  cent 

Conservation  of  Labor  by  Convenient  Arrangement  of 
Farm  Buildings.  It  is  difficult  to  estimate  the  saving  of  labor 
which  will  result  from  buildings  convenient  in  themselves  and 
in  their  relation  to  one  another.  This,  however,  is  an  impor- 
tant matter,  because  the  loss  on  account  of  inconvenience  is 
accumulative,  and  the  aggregate  for  a  year  is  large.    Thus 

395 


396  AGRICULTURAL  ENGINEERING 

the  total  distance  covered  in  a  year  in  walking  300  feet  and 
return  four  times  a  day  is  over  145  miles,  and  a  saving  of 
30  minutes  every  day  for  a  year  is  equal  to  nearly  19  days 
of  ten  hours  each.  As  far  as  possible  the  arrangement  of  farm 
buildings  should  follow  the  principles  incorporated  in  modern 
shops  and  factories. 

Comfortable  buildings  conserve  feed  to  such  an  extent 
that  under  modern  conditions  it  is  practically  impossible  to 
produce  meat  or  dairy  products  profitably  without  them.  It 
is  true  that  authorities  differ  on  this  point.  Some  maintain 
that  protection  from  temperature  changes  is  not  of  great  im- 
portance for  successful  beef  production,  but  all  agree  that 
protection  from  wind  and  wet  is  essential.  Sanitary  farm 
buildings  maintain  the  health  of  farm  animals.  Pure  air  is 
as  essential  as  good  food.  Poor  ventilation  furnishes  the 
best  conditions  for  disease  germs  to  flourish,  while  proper 
lighting  dispels  disease  by  destroying  germs.  The  best 
quality  of  milk  cannot  be  produced  in  unsanitary  barns. 

Laying  Out  the  Farm.  By  the  laying  out  of  the  farm  is 
meant  the  arrangement  and  location  of  the  fields,  buildings, 
and  lots.  This  is  a  subject  which  naturally  precedes  the 
arrangement  and  design  of  farm  buildings,  for  it  is  well-nigh 
impossible  to  consider  one  farm  building  fully  without  taking 
into  account  its  relation  to  other  buildings  and  to  the  fields 
of  the  farm  on  which  it  is  located. 

The  proper  arrangement  of  a  farm  is  fundamental  in 
securing  convenience,  system,  and  economy  in  its  operation 
and  management,  and  may  determine  the  success  or  failure 
of  the  enterprise. 

In  laying  out  the  farm  an  almost  endless  number  of  condi- 
tions must  be  considered,  among  which  may  be  mentioned: 

1.  The  amount  of  good  and  poor  land. 

2.  The  location  of  the  hills. 


FARM  STRUCTURES 


397 


3.  The  location  of  the  woodland. 

4.  The  location  of  water. 

5.  The  natural  drainage. 

6.  The  original  shape  of  the  tract. 
The  features  to  be  desired  are : 

1.  Convenience  of  access,  economy  of  fencing,  and  con- 
venience of  rotation,  of  the  fields. 

2.  Convenience  of  relation  to  one  another,  to  the  fields, 
to  the  lots,  and  to  the  highways,  of  the  buildings. 

A  map  of  the  farm  showing  location  of  buildings,  lots, 
fields,  streams,  roads,  and  draining  is  very  helpful.     Each 


/\       Poor 

from    Town  ■-~« 

Morninq 

To  Field*  «>t44.444. 


PoTATOt«. 


(»*3  &  Grove,  g  *a  9  is  *?  ** 

t?<53  ■«>  <3<»Ce>0    la   rS,  tsi    is  vO 
<3    (SBW>  «>    «3     tS    «   53  «0  «0 


i  l»    &   &  »<»^GR0VE    <3  £3  <5@^9 


/         Granabv 


Cow 
She.0 

Bf\RN 


Fig.  253.     An  Inconvenient  arrangement  of  farm  buildings. 


field  should  be  designated  by  a  particular  name  or  number 
and  the  exact  acreage  indicated.  Such  a  map  is  extremely 
useful  in  planning  the  operations  of  the  farm,  the  rotations, 
and  in  calculating  the  amounts  of  fertiUzers,  seed,  etc. 


898 


AGRICULTURAL  ENGINEERING 


/\    GOOD 
ARRRNGEMFNIT 

rrotrt     Town     ~ 
To  FieJiSs      .... 


VtoRSES, 


To  illustrate  the  great  differences  to  be  observed  in  farm- 
stead plans,  attention  is  called  to  the  two  accompanying 
sketches.  The  first  of  these  (Fig.  253)  is  the  plan  of  a  farm- 
stead just  as  it  is  at  the  present  time.  To  do  the  morning 
chores  on  this  farm, — tending  to  the  horses,  cows,  and  hogs — 
it  is  necessary  to  walk  2400  feet  outside  of  the  buildings. 
Besides  this  bad  feature  notice  how  inconveniently  the  garden 

is  placed  from  the 
house.  The  well,  also, 
instead  of  being  be- 
tween the  house  and 
barn,  is  beyond  the 
barn. 

Compare  this  plan 
with  the  next.  The 
house  is  150  feet  from 
the  road  and  the  barn 
is  200  feet  from  the 
house,  which  is  not  too 
close  when  located  in 
the  right  direction. 
The  prevailing  winds 
are  either  from  the 
northwest  or  south- 
east, and  the  odors 
from  the  bam  are  seldom  carried  toward  the  house.  The 
implement  and  wagon  shed  also  includes  the  shop  and 
the  milkhouse.  If  the  well  could  be  located  near  this  shop, 
so  much  the  better,  as  at  this  point  a  gasoline  engine  could 
be  used  to  do  all  the  Hght  work.  In  doing  the  morning  work, 
a  man  needs  to  walk  only  900  feet,  a  saving  of  1500  feet 
over  the  former  plan. 


sa  ^  «i 

^.  ^  ^ 


PUbuo 


HlOHWRY. 


Fig.  254.  A  good  arrangement  of  farm 
buildings.  The  lines  of  travel  in  doing  the 
work  of  the   farm  are  indicated. 


FARM  STRUCTURES  399 

Principles  of  Location.  In  locating  the  farm  buildings,  it 
is  well  to  incorporate  as  many  as  possible  of  the  following 
principles  in  the  plan : 

1.  Have  the  buildings  near  the  center  of  the  farm,  giving 
due  consideration  to  other  advantages. 

2.  Needless  fences  should  be  avoided,  on  account  of  first 
cost  and  the  cost  of  maintenance. 

3.  A  pasture  should  be  adjacent  to  buildings. 

4.  The  buildings  should  occupy  the  poorest  ground. 

5.  The  buildings  should  be  located  with  reference  to  the 
water  supply. 

6.  The  buildings  should  be  on  a  slight  elevation  when- 
ever possible. 

7.  A  southwest  slope  is  desirable. 

8.  The  soil  on  which  buildings  are  to  be  placed  should 
be  dry  and  well  drained. 

9.  A  timber  windbreak  should  be  secured. 

10.  A  garden  plot  should  be  near  thehouse. 

11.  The  buildings  should  not  be  located  on  high  hills, 
because  of  difficulty  of  access  from  fields  and  roads. 

12.  The  buildings  should  not  be  placed  in  low  valleys, 
on  account  of  the  lack  of  air  and  good  drainage  and  the 
danger  from  frost. 

13.  The  buildings  should  be  located  on  the  side  of  the  farm 
nearest  the  school,  church,  or  town. 

14.  The  house  should  not  be  less  than  100  feet  from  the 
highway. 

15.  The  barn  should  be  about  150  to  200  feet  from  the 
house,  and  not  in  the  direction  of  the  prevailing  winds. 

16.  The  barn  should  be  in  plain  view  from  the  house. 

17.  The  lots  should  be  on  the  farther  side  of  the  barn 
from  the  house. 

18.  Several  views  from  the  house  are  desirable. 


400  AGRICULTURAL  ENGINEERING 

19.  All  buildings  should  serve  as  windbreaks. 

20.  The  shop  and  machine  shed  should  be  convenient  to 
the  house,  the  barn,  and  the  fields. 

Two  general  systems  of  arranging  farm  buildings  have 
been  developed  in  this  country.  For  want  of  better  terms, 
they  may  be  designated  as  the  distributed  system,  in  which  a 
separate  building  is  provided  for  each  kind  of  stock  or  for 
each  purpose  to  which  it  may  be  devoted;  and  the  concen- 
trated system,  in  which  everything  is  placed  under  one  roof  as 
far  as  possible,  or  the  buildings  are  at  least  connected.  The 
advantages  of  the  first  system  may  be  stated  as  follows : 

1.  A  greater  amount  of  lot  room  is  possible. 

2.  Different  kinds  of  animals  are  separated. 

3.  There  is  less  destruction  in  case  of  fire. 

4.  It  is  more  economical  for  the  storage  of  certain  crops 
and  machinery. 

5.  Better  lighting  is  secured:  wide  barns  are  necessarily 
dark. 

In  turn,  the  following  arguments  maybe  advanced  for  the 
concentrated  system : 

1.  The  first  cost  is  less :  needed  space  is  secured  with  the 
minimum  of  wall  surface. 

2.  There  is  less  expense  for  maintenance. 

3.  It  is  more  economical  of  labor. 

4.  Better  fire  protection  can  be  provided. 

5.  Manure  can  be  handled  to  the  best  advantage. 

6.  It  provides  a  very  imposing  structure. 

It  is  to  be  expected  that  opinions  and  tastes  will  differ,  as 
well  as  conditions,  and  all  of  these  will  determine  the  best 
arrangement  for  any  particular  location.  Most  farmsteads 
are  the  result  of  growth  and  development,  and  for  this  reason 
are  not  what  they  would  be  if  built  entirely  at  one  time.  As 
changes  are  made  and  new  buildings  constructed  it  is  well  to 


FARM  STRUCTURES  401 

keep  in  mind  the  desired  features  and  to  approach  the  ideal  as 
far  as  possible. 

In  commercial  life  it  has  often  been  found  a  matter  of 
good  business  to  dismantle  certain  buildings  designed  for 
manufacture  and  entirely  rebuild  them.  There  are,  no  doubt, 
many  farms  so  equipped  that  it  would  be  a  good  business 
investment  to  entirely  dismantle  the  existing  buildings  and 
rebuild  in  such  a  way  as  to  insure  a  more  economic  operation. 

QUESTIONS 

1.  Give  four  reasons  why  the  study  of  farm  structures  is  impor- 
tant. 

2.  What  percentage  of  the  fixed  capital  of  the  farm  is  invested  in 
farm  buildings? 

3.  Explain  how  a  convenient  arrangement  of  farm  buildings  con- 
serves labor. 

4.  In  what  way  will  comfortable  buildings  conserve  feed? 

5.  How  is  the  quahty  of  dairy  products  influenced  by  the  character 
of  the  farm  buildings? 

6.  Upon  what  general  conditions  will  the  layout  of  the  farm  depend? 
7  What  are  the  principal  features  to  be  desired  in  the  layout  of 

a  farm? 
.    8.  What  are  some  of  the  principles  involved  in  laying  out  the  farm? 
9.  Discuss  the  distributed  system  of  farm  buildings. 
10.  X)iscuss  the  concentrated  system  of  farm  buildings. 


CHAPTER  LXIIl 
MECHANICS  OF  MATERIALS 

Definitions.  Mechanics  is  that  science  which  treats  of 
the  action  of  forces  upon  bodies  and  the  effects  which  they 
produce. 

Statics  is  that  division  of  the  science  of  mechanics  which 
treats  of  the  forces  acting  on  a  body  at  rest,  or  in  equiUbrium. 
In  architectural  design,  statics  is  the  principal  branch  of 
mechanics  to  be  considered,  as  nearly  all  the  forces  involved 
are  those  of  rest. 

Action  of  a  Force.  A  force  acting  upon  a  body  tends  to 
produce  motion  in  two  ways : 

1.  It  tends  to  produce  motion  in  the  direction  of  the 
force. 

2.  If  a  point  of  the  body  be  fixed,  it  tends  to  produce 
motion  about  that  point. 

Condition  of  Equilibrium.  Since  a  force  acting  upon  a 
body  tends  to  produce  motion  in  two  ways,  the  following 
conditions  must  be  filled  in  order  that  equiUbrium  exist : 

1.  The  resultant  of  all  the  forces  tending  to  move  the 
body  in  any  direction  must  be  zero. 

2.  The  resultant  of  all  the  forces  tending  to  turn  the  body 
about  any  point  must  be  zero. 

The  moment  of  a  force  about  a  point  is  the  product  of  the 
force  into  the  perpendicular  distance  from  the  line  of  the 
force  to  the  point. 

Moments  tending  to  produce  clockwise  rotation  are  called 
positive  moments,  and  those  tending  to  produce  counter- 
clockwise motion,  negative  moments. 

402 


FARM  STRUCTURES 


403 


Tension 
Figr.      255.        A 
sketch     illustrat- 
ing       a        tensile 
stress. 


-ten- 


Equilibrium  of  Moments.  The  forces  acting  upon  a  body 
are  in  equilibrium  when  the  algebraic  sum  of  their  moments 
about  any  one  point  is  equal  to  zero. 

Stress.  A  stress  is  the  resistance  offered  by  a  rigid  body 
to  an  external  force  tending  to  change  its 
form.  A  rope  suspending  a  weight  is  under 
stress.  If  a  section  of  the  rope  be  taken  at 
any  point,  the  force  exerted  by  the  part  of  the 
rope  on  one  side  of  the  section  on  the  part  on 
the  other  side  to  prevent  the  rope  from  part- 
ing or  breaking,  is  termed  the  stress  at  a  section. 
The  word  strain  is  often  used  incorrectly  for 
stress,  but  strain  is  the  change  of  form  pro- 
duced by  a  stress.  Simple  stresses  are  of  three  kinds, 
sile,  compressive,  and  shearing. 

Stresses  are  measured  in  pounds  or  tons  in  countries  using 
English  units.    The  pound  is  the  more  often  used. 

Tensile  stresses  are  those  tending  to  pull 
the  object  or  material  in  two,  or  to  stretch  it. 
A  rope  suspending  a  weight  is  under  a  tensile 
stress.  A  tie  rod  in  a  truss  is  subjected  to 
tensile  stress. 

Compressive  Stresses.  Compressive  stresses 
are  those  tending  to  crush  the  object  or  ma- 
terial, as  the  load  that  is  placed  on  a  column 
or  on  a  foundation. 

Shearing  Stresses.  Shearing  stresses  are 
those  tending  to  sUde  one  portion  r  ,  f  f '  ^  ^ — \\  \^ — » 
of  the  material  over  another,  or  ^^^  257.  a  sketch  niustrat. 
when  there  is  a  tendency  to  cut.  *"^  *  shearing  stress. 

The  stress  on  riveted  joint  is  a  good  example. 

Complex  Stresses.  Complex  stresses  are  those  formed 
by  a  combination  of  simple  stresses.  The  stresses  in  beams 
are  usually  complex. 


777777777777777 

Compreasion 

Fig.  256.  A 
sketch  illustrat- 
ing a  compres- 
sive stress. 


404  AGRICULTURAL  ENGINEERINO 

Unit  stress  is  the  stress  per  unit  area.  Stresses  are 
usually  measured  in  pounds,  and  areas  in  square  inches.  The 
total  stress  divided  by  the  area  of  cross-section  in  square 
inches  will  give  the  unit  stress. 

-I 

when  P   =  total  stress  in  pounds. 

A  =  area  of  cross- section  in  square  inches. 
S   =  unit  stress. 

This  rule  is  apphed  only  when  the  total  stress  is  uniformly 
distributed  and  the  stress  is  a  simple  stress. 

Elasticity.  Most  bodies  when  subjected  to  a  stress  will 
be  deformed.  The  amount  the  body  is  changed  in  shape  is 
termed  the  deformation.  An  elastic  body  will  regain  its 
former  shape  when  a  stress  is  removed,  if  it  has  not  been  too 
great.  Up  to  a  certain  limit  the  amount  of  change  in  shape  is 
proportional  to  the  stress.  If  the  unit  stress  be  increased  to 
such  an  extent  that  the  material  will  not  regain  its  original 
shape  after  being  deformed,  the  stress  has  passed  beyond  the 
elastic  limit  of  the  material. 

Ultimate  Strength.  If  the  unit  stress  of  any  material  be 
increased  until  rupture  or  breakage  occurs,  the  stress  pro- 
ducing the  failure  is  the  ultimate  strength  of  the  material. 
If  the  failure  be  produced  by  the  tensile  stress,  the  ultimate 
tensile  strength  is  obtained.  In  like  manner  the  ultimate 
compressive  and  shearing  strengths  are  obtained.  The 
breaking  load  divided  by  the  original  cross- section  gives  the 
ultimate  strength. 

Working  Stress.  The  greatest  stress  allowed  in  any  part 
of  a  framed  structure  is  called  the  working  stress  of  that  part. 
In  turn,  the  working  strength  of  a  material  to  be  used  for  a 
certain  purpose  is  meant  the  highest  unit  stress  to  which 
the  material  ought  to  be  subjected  when  so  used. 


FARM  STRUCTURES 


405 


Factor  of  Safety.    The  factor  of  safety  is  the  ratio  of  the 
ultimate  strength  to  the  working  stress  of  a  material. 

S 


when  S  =  ultimate  strength,  s  =  working  strength,  f  =  factor  of  safety. 

The  engineer  in  charge  of  design  is  called  upon  to  decide 
the  factor  of  safety  to  be  used. 

The  factor  of  safety  should  (1)  be  much  below  the  elastic 
limit,  (2)  be  larger  for  varying  loads,  (3)  be  larger  for  non- 
uniform materials. 

Factors  of  safety  for  various  materials. 


Materials 

For  steady 

stress. 
Buildings 

For  varying 
stress. 
Bridges 

For  shocks. 
Machines 

Timber 

8 
15 
6 
4 
5 

10 

25 

15 

6 

7 

15 

Brick  and  stone 

30 

Cast-iron 

20 

Wrought  iron 

10 

Steel  

15 

This  table  is  taken  from  an  architect's  handbook,  and  the 
factors  of  safety  here  recommended  are  nearly  twice  as  large 
as  are  commonly  used  in  designing  farm  structures. 
QUESTIONS 

1.  Define  mechanics.     Define  statics. 

2.  In  what  two  ways  does  a  force  acting  on  a  body  tend  to  produce 
motion? 

3.  What  are  the  two  conditions  for  equilibrium? 

4.  Define  moment  of  force. 

5.  When  does  an  equilibrium  of  moments  exist? 

6.  Define  stress.    Define  strain. 

7.  Describe  a  tensile  stress.    A  compressive  stress.    A   shearing 
stress.    A  complex  stress.     Define  unit  stress. 

8.  Explain  what  is  meant  by  the  elastic  limit  of  a  material. 

9.  Define  ultimate  strength.    Working  stress.    Factor  of  safety. 
10.  Upon  what  conditions  will  the  size  of  the  factor  of  safety  depend? 


CHAPTER  LXIV 

MECHANICS  OF  MATERIALS  AND  MATERIALS   OF 
CONSTRUCTION 

The  Strength  of  Beams.  The  strength  of  a  beam  or  its 
abiUty  to  support  a  load  depends  upon  three  principal  factors : 
(1)  The  way  the  beam  is  stressed,  or  the  way  the  load  is 
applied  or  distributed  and  the  beam  supported;  (2)  the  way 
the  material  is  arranged;  and  (3)  the  kind  of  material.  These 
factors  are  represented  by  the  maximum  bending  moment, 
the  modulus  of  section,  and  the  modulus  of  rupture. 

The  Bending  Moment.  The  bending  moment  is  a  meas- 
ure of  the  stresses  acting  on  a  beam.  Suppose  a  beam  to  be 
fixed  solidly  at  one  end,  as  would  be  the  case  if  it  extends 
into  a  solid  wall,  and  a  load  or  a  weight  to  be  suspended  at  the 
extreme  end,  as  shown  in  Fig.  258.     It  is  to  be  noted  that  the 

greatest  stress  in  the  beam  would 
be  at  the  point  where  it  enters 
the  wall.  The  force  would  tend 
to  rotate  the  beam  about  a  point 
in  the  beam  where  it  enters  the 

a^a^ntil'v^rteartl'^reLm    Wall.      The  StrCSSeS produced  WOUld 

tre'rtfon'ii^i^ioldarthe'fTee  tend  to  pull  the  material  in  two 
^^^'  at  the  upper  side  and  to  crush  it 

on  the  lower.  If  the  weight  be  placed  somewhere  between 
the  wall  and  the  end,  the  stress  on  the  beam  would  be  less 
than  in  the  first  instance;  in  fact,  the  stress  would  be  in  direct 
proportion  to  the  distance  from  the  wall  to  the  weight.  The 
stress  would  also  be  in  direct  proportion  to  the  size  of 
the  weight.    Thus  the  tendency  to  break  the  beam,  or  the 

406 


FARM  STRUCTURES  407 

stress  at  the  wall,  would  be  twice  as  great  for  a  20-pound 
load  as  for  a  10-pound  load.  It  is  to  be  noticed  that  the  stress 
would  be  greater  at  the  point  where  the  beam  enters  the 
wall  than  at  any  other  point;  or,  in  other  words,  the  maxi- 
mum bending  moment  would  exist  at  that  point. 

Expressed  in  the  form  of  a  formula: 
B  M  =  W  L 

where  B  M  is  the  maximum  bending  moment,  W  the  weight,  and 
L  the  length  of  beam  in   inches. 

If  the  beam  be  supported  at 
both  ends  or  extend  into  the  wall 
at  both  ends,  the  maximum  bend- 
ing moment  would  have  an  entire- 

Iv  HifFprpnt  VflliiP-  thim  for  «  ..^'^-  -^^^r  ^  ^^^*^^  illu?trating 
ly     Uinerent    Vame,     tnUS,     lOr    a     the  action  of  a  concentrated  load  at 

beam  resting  in  supports  at  both  '^' '''''''  °^ "  ^^^^^^^  ^^*"^- 
ends  with  a  load  at  the  center, 

B  M  =  M  WL 

If  the  load  be  uniformly  distributed  over  the  beam,  then 
B  M  =  3^  W  L 

The  Modulus  of  Section.  It  is  generally  known  that  a 
2x4  piece  of  wood  will  support  a  greater  load  when  placed  on 
edge  than  when  laid  flat.  The  modulus  of  section  is  simply 
a  measure  of  the  strength  of  a  beam  according  to  the  arrange- 
ment of  the  material.  Thus,  for  a  beam  with  a  rectangular 
cross-section, 

M  S  =  — 
6 

where  M  S  is  the  modulus  of  section,  6  the  width  of  the  beam  in 
inches,  and  d  the  depth  of  the  beam  in  inches. 

Thus  it  is  seen  that  a  2x4-inch  beam  is  twice  as  strong 
when  set  on  edge  as  when  laid  on  the  flat;  for,  when  placed 
on  edge, 

hd""        2X(4X4)     32 


M  S  =  -— 


6  6  6 


408 


AGRICULTURAL  ENOINEERINQ 


If  placed  on  the  flat, 

W        4X(2X2)     16 

M  S   =  —  =  = — 

6  6  6 

or  just  one-half  of  the  value  previously  obtained. 

The  Modulus  of  Rupture.    The  modulus  of  rupture  is  a 

measure  of  the  strength  of  the  material  to  resist  transverse 

or  bending  stresses.    Thus  oak  is  stronger  than  pine.    The 

modulus  of  rupture  is  obtained  by  test.    The  following  table 

furnishes  the  values  of  the  modulus  of  rupture  quite  generally 

used.    All  of  the  values  are  per  square  inch  of  cross-section. 

White  pine 7,900 

Yellow  pine 10,000 

Oak 13,000 

Hickory 15,000 

Cast-iron 45,000 

Mild  steel 55,000 

Formula  for  Beams.    The  general  formula  for  beams  may 

now  be  stated  as  follows: 

modulus  of  selection  X  rupture  modulus 

Bendmg  moment  = ;: — ;: 

factor  of  safety 

This  formula  may  be  used  in  calculating  the  strength  of 
beams,  but  it  is  given  here  principally  to  explain  how  the 
strength  of  beams  varies.  The  following  tables  give  the 
strength  of  columns  or  posts  and  of  beams. 

Safe  Strength  of  White  Pine  Beams.  The  following 
table  gives  the  safe  loads  for  horizontal,  rectangular  beams 


Span  in 

feet 

Depth  of 

beam 

6 

8 

10 

12 

14 

16 

6 

720 

540 

432 

360 

308 

7 

980 

735 

588 

490 

420 

8 

1280 

960 

768 

640 

548 

480 

10 

2000 

1500 

1200 

1000 

857 

750 

12 

2880 

2160 

1728 

1440 

1234 

1080 

14 

3920 

2940 

2352 

1960 

1680 

1470 

FARM  STRUCTURES 


409 


one  inch  wide  with  loads  uniformly  distributed.  If  the  load 
be  concentrated  at  the  center,  divide  by  two. 

For  oak  or  Northern  yellow  pine,  the  tabular  values  may 
be  multipUed  by  IJ^;  for  Georgia  yellow  pine,  by  1^. 

For  a  discussion  of  the  materials  used  in  the  construction 
of  farm  machinery,  see  Chapter  XXXI. 

Safe  Load  in  Pounds  for  White  Pine  or  Spruce  Posts.* 


Siie  of  post 
in  inches 

Length  of  post  in  feet 

8 

10 

12 

14 

16 

4x4 

4x6 

5}^  round. 

6x6 

6x8 

6x10 

7}^  round. 

8x8 

8x10 

8x12 

9>^  round. 
10x10 

7,680 

11,520 
12,350 
19,080 
25,440 
31,800 
24,220 
35,450 
44,320 
53,180 
40,000 
62,500 

7,033 
10,550 
11,730 
18,216 
24,290 
30,360 
23,380 
34,300 
42,480 
51,450 
39,000 
55,400 

6,533 
9,800 
11,180 
17,352 
23,140 
28,920 
22,540 
33,150 
41,440 
49,730 
37,860 
53,960 

8,700 
10,490 
16,490 
21,980 
27,480 
21,660 
32,000 
40,000 
48,000 
36,800 
52,520 

15,620 
20,830 
26,040 
20,820 
30,850 
38,560 
46,240 
35,730 
51,080 

Oak  and  Norway  pine  posts  are  about  one-fifth  stronger, 
and  Texas  pine  and  white  oak  are  one-third  stronger. 

Stone.  Limestone  and  sandstone  are  the  kinds  of  stone 
generally  used  for  building  purposes.  Granite  is  used  to  a 
limited  extent.  Limestone  is  the  most  common  stone  used, 
and  when  dense  and  compact  is  very  durable.  It  often  con- 
tains certain  substances  which  cause  the  stone  to  become 
badly  stained  after  being  in  use  for  a  time.  Limestone  has 
an  average  compressive  strength  of  about  15,000  pounds  per 
square  inch  and  weighs  from  155  to  160  pounds  per  cubic  foot. 


♦Kidder's  Pocket  Book. 


410 


AGRICULTURAL  ENGINEERING 


Sandstone  of  a  good  grade  is  an  excellent  building  mate- 
rial. It  has  a  strength  of  about  11,000  pounds  per  square 
inch  and  weighs  about  140  pounds  per  cubic  foot. 

The  densest  and  strongest  stones  are  the  most  durable,  as 
a  rule.  A  good  stone  will  not  absorb  more  than  5  per  cent 
of  its  weight  of  water  when  soaked  in  water  for  24  hours. 

Brick.  Brick  is  a  material  quite  generally  used  over  the 
country,  and  when  of  a  good  quality  is  quite  satisfactory. 
Brick  should  be  of  uniform  size,  true  and  square,  and  when 
broken  should  show  a  uniform  and  dense  structure.  Good 
brick  will  not  absorb  moisture  to  an  extent  greater  than  10 

per  cent  of  its  weight, 
and  the  best  will  absorb 
less  than  5  per  cent. 
The  crushing  strength 
of  brick  should  exceed 
4000  pounds  per  square 
inch. 

Hollow  clay  blocks 
or  tile  are  made  of  the 
same  material  as  brick, 
and  should  have  the  same  characteristics.  Clay  blocks  are 
lighter  than  brick,  and  so  the  cost  of  shipping  is  less.  They 
cost  less  by  volume,  and  more  wall  can  be  laid  in  a  given  time 
than  with  common  brick. 

Lime.  Lime  is  used  in  mortar  where  the  greater  dura- 
bility and  strength  of  cement  mortar  are  not  needed.  Quick 
lime  should  be  in  large  lumps  and  should  be  free  from  cinders 
and  dust.  When  slackened  with  water  it  should  form  a 
smooth  paste  without  lumps  or  residue.  Lime  mortar  is 
usually  made  of  1  part  of  lime  to  2  or  3  of  sand. 

Portland  Cement.  Portland  cement  is  now  generally  used 
in  the  making  of  mortar  and  concrete.     It  should  be  finely 


Fig.    260.     Hollow    clay   building    blocks. 


FARM  STRUCTURES 


411 


ground  and  should  set  or  harden  neither  too  quickly  nor  too 
slowly.  It  should  show  a  high  tensile  strength  when  hard- 
ened and  sufficiently  aged.  It  should  not  check,  crack,  or 
crumble  upon  hardening.  Where  cement  is  to  be  used  in 
considerable  quantities  it  should  be  carefully  tested  by 
standard  tests. 

Sands.  Sand  should  be  clean,  durable,  coarse,  and  free 
from  vegetable  and  other  foreign  matter.  Coarse  sand  is 
preferable  to  jfine  sand  because  the  percentage  of  voids  or 
open  space  between  the  sand  grains  is  less. 

Concrete.  In  a  general  way  concrete  consists  of  mortar 
in  which  there  is  imbedded  more  or  less  coarse  material,  like 


^/1A/0 


^TO/V£r 


COA/C/^ST^- 


Flgr.   261.     Material  required  to  make  concrete  to  the  proportion  of 
1   part  of  cement,  2   parts  of  sand,  and  4  parts  of  broken  stone. 

gravel  or  broken  stone,  called  the  aggregate.  Thus  it  is  seen 
that  if  the  aggregate  be  good,  durable  material  and  the  mortar 
be  sufficient  in  quantity  to  surround  all  of  the  aggregate,  the 
whole  will  be  as  strong  as  the  mortar.  In  preparing  concrete, 
therefore,  it  is  desirable  to  obtain  as  dense  a  mixture  as  is 
practical. 

The  mixtures  indicated  in  the  following  table  are  in  com- 
mon use,  and  the  amount  of  material  required  to  make  a 
cubic  yard  of  concrete  in  each  case  is  also  given. 

A  rich  mixture  is  used  for  beams,  columns,  and  water-tight 
constructions. 


412  AGRICULTURAL  ENGINEERING 

Material  for  one  yard  of  concrete  of  different  proportions. 


Mixture 

Proportions 

Cement,  bbls. 

Sand,  bbls. 

Gravel,     bbla. 

Rich 

1:2:4 
1:2>^:5 
1:3:6 
1:4:8 

1.57 
1.29 
1.10 

.85 

3.14 
3.23 
3.30 
3.40 

6.28 

Medium 

Ordinary 

Lean 

6.45 
6.60 
6.80 

Additional  data:  1  bbl.  of  Portland  cement  weighs  376  lbs.;  a 
sack,  94  lbs.  A  barrel  contains  3.5  cu.  ft.  between  heads.  Concrete 
weighs  about  150  lbs.  per  cu.  ft. 

A  medium  mixture  is  used  for  thin  foundation  walls  and 
for  floors  and  sidewalks. 

An  ordinary  mixture  is  used  for  heavy  walls  which  are 
not  subject  to  heavy  strains. 

A  lean  mixture  is  used  for  heavy  work  where  the  material 
is  subjected  to  only  compressive  stresses. 

Reinforcement.     Concrete  is  a  very   good   material  to 

carry  compressive  stresses.     Concrete  and  steel  have  very 

r.^^.  ^  nearly  the  same  coefficient  of  ex- 

.^^^^^^^      f.L         pansion  for  changes  in  tempera- 

"""^^^        ^^  ture.    This  makes  possible  the  use 

Fig.    262.    Sketch    showing  of  a  combiuatiou  of j  thcse  mate- 

the   proper  location  of  steel   in      .    ,       .        .,  i        j.         i 

a  concrete  slab  to  resist  tensile  rials  to  the  vcry  Dest  advantage 

stresses  due  to  bending.  .  i      m  t  i  i-  rT^^ 

m  buildmg  construction.  The 
steel  is  placed  in  position  to  resist  tensile  stresses  to  the 
best  advantage,  and  the  concrete  is  poured  around  it. 
When  used  economically  the  cross-sectional  area  of  the  steel 
is  equal  to  }^  to  1  per  cent  of  the  cross-sectional  area  of  the 
beams.  The  steel  is  usually  placed  from  ^  to  1  inch  be- 
neath the  surface  of  the  concrete,  in  order  to  be  thor- 
oughly protected  from  corrosion. 


FARM  STRUCTURES  413 

QUESTIONS 

1.  Upon  what  three  factors  does  the  strength  of  a  beam  depend? 

2.  Define  maximum  bending  moment. 

3.  What  is  the  maximum  bending  moment  for  a  beam  120  inches 
long  and  loaded  at  the  center  with  1000  pounds? 

4.  Define  modulus  of  section. 

5.  What  is  the  modulus  of  section  for  a  2x6? 

6.  Define  modulus  of  rupture. 

7.  What  is  the  modulus  of  rupture  for  white  pine?  Oak?  Cast 
iron? 

8.  Give  the  general  formula  for  beams. 

9.  What  load  will  a  2x6  white  pine  beam  carry  if  the  beam  be  10 
feet  long  and  the  load  be  concentrated  at  the  center?  If  the  load  ba 
uniformly  distributed? 

10.  Give  the  principal  characteristics  of  the  following  building 
materials:  stone,  brick,  hme,  Portland  cement,  sand,  concrete. 

11.  Explain  rich,  medium,  ordinary,  and  lean  mixtures,  and  the 
use  of  each. 

12.  Explain  the  principles  involved  in  the  reinforcing  of  concrete. 


CHAPTER  LXV 
HOG  HOUSES 

Essentials.  The  essentials  of  a  good  hog  house  are 
warmth  in  winter,  coolness  in  summer,  dryness,  good  ventila- 
tion, and  adequate  light.  In  addition  it  should  be  so  arranged 
and  located  as  to  be  convenient  not  only  for  caring  for  the 
animals  but  also  for  securing  pasturage.  A  building  which 
thoroughly  protects  the  hogs  from  the  wind  and  moisture  is 
considered  warm  enough  for  all  but  the  colder  climates.  Far- 
rowing houses  must,  of  course,  be  made  warm. 

Location.  Drainage  is  highly  important,  and  a  well- 
drained  location  should  always  be  selected.  If  the  soil  is  of 
a  porous  or  gravelly  nature,  it  will  make  a  more  desirable  site. 

Tjrpes  of  Hog  Houses.  There  are  two  general  types  of 
hog  houses  in  common  use.  The  first  type  is  the  individual 
or  colony  hog  house,  or  cot,  as  it  is  sometimes  called,  which  is 
usually  made  portable  and  of  sufficient  size  to  accommodate 
one  sow  at  farrowing  time  or  one  litter  of  pigs  as  they  grow  to 
maturity. 

The  second  type  is  the  large  or  concentrated  hog  house, 
sometimes  called  the  combined  hog  house,  or  piggery,  and  pro- 
vides several  pens  under  one  roof.  This  type  of  building  is 
of  more  elaborate  construction,  and  in  many  instances  special 
care  is  used  in  the  construction  to  secure  a  warm  building  for 
farrowing  early  litters. 

Advantages  of  the  Colony  House.  There  is  much  differ- 
ence of  opinion,  even  among  practical  hog  raisers  and  breed- 
ers, in  regard  to  the  relative  merits  of  the  two  types  of  hog 

414 


FARM  STRUCTURES  416 

houses  which  have  been  described.     The  advantages  of  the 
individual  or  colony  house  may  be  summarized  as  follows : 

1.  Each  sow  is  free  from  disturbance  at  farrowing  time. 

2.  Each  litter  is  reared  by  itself,  and  too  many  pigs  are 
not  placed  in  a  common  lot. 

3.  The  house  may  be  placed  at  the  opposite  end  of  the 
lot  from  the  feed  trough,  thus  requiring  the  hogs  to  exercise. 

4.  There  is  less  danger  of  spreading  disease,  owing  to  the 
fact  that  each  family  is  quite  effectively  isolated. 

5.  If  the  location  of  the  house  becomes  unsanitary,  it 
may  be  moved. 

Advantages  of  the  Large  Hog  House.  The  following 
advantages  may  be  claimed  for  the  large  or  concentrated 
hog  house. 

1.  This  type  is  almost  essential  for  early  litters  in  north- 
em  cUmates.  It  is  possible  to  construct  a  warmer  building  to 
begin  with,  and,  if  necessary,  artificial  heat  may  be  provided 
by  means  of  a  stove  or  heating  plant. 

2.  It  saves  time  in  handling  and  feeding  the  pigs.  In 
other  words,  less  time  is  lost  going  from  pen  to  pen.  The 
distribution  of  feed  and  water  becomes  a  big  task  where  there 
are  many  pens  to  look  after  and  where  they  are  located  at 
some  distance  from  one  another. 

3.  The  concentrated  house  saves  fencing. 

4.  The  large  house  is  generally  of  more  durable  con- 
struction and  of  better  appearance,  adding  thereby  to  the 
value  of  the  farm. 

5.  It  permits  of  larger  pastures,  which  are  more  con- 
venient to  renew  or  cultivate  when  rotated  with  other  crops. 

Both  types  of  houses  are  successfully  used  by  practical 
men,  and  the  type  to  be  chosen  must  depend  upon  local  condi- 
tions and  individual  tastes. 


416 


AGRICULTURAL  ENGINEERING 


Dimensions.  A  farrowing  pen  should  contain  from  40 
to  140  square  feet  of  floor.  A  common  size  is  8  by  10  feet. 
Stock  hogs  should  have  6  to  12  square  feet  of  floor,  varying 
with  their  age.  A  farrowing  pen  usually  has  an  outside  pen, 
also,  having  an  area  of  from  128  to  160  square  feet  or  more. 


Q'-O"- 


Fig.    263.     Front    elevation    of    the    "A"    type    of    colony    or    portable 
hog  house.      (After  Wisconsin  Exp.  Sta.) 


The  cubic  feet  of  air  space  per  hog  is  not  taken  into  consider- 
ation. Portable  or  individual  hog  houses  are  usually  6  by  8 
feet  or  8  by  8  feet. 

When  ventilating  flues  are  provided,  about  8  square  inches 
of  cross-section  should  be  provided  for  each  grown  animal. 


FARM  STRUCTURES 


417 


THE  INDIVIDUAL  HOG  HOUSE 

Construction.  The  individual  hog  house  is  constructed 
in  a  variety  of  shapes,  of  which  the  more  general  are  the 
A-shaped  house  and  the  shed-  and  the  gable-roofed  houses. 
There  does  not  seem  to  be  a  great  difference  in  the  merits  of 
one  shape  over  the  other. 

The  A-shaped  house  has  the  walls  and  roof  combined.  It 
is  usually  made  of  1x12  boards,  with  the  cracks  covered  with 
battens.  The  door  should  be  about  2  feet  wide  and  2  feet  6 
inches  high.  A  small  window  is  usually  located  at  each  end 
of  the  house.  A  small  ventilator  in  the  ridge  of  the  roof  is 
desirable.  It  is  recommended  that  the  door  be  covered  with 
burlap  to  prevent  drafts  in  cold  weather.    Some  breeders 


—  ir- 

zzzz 



I 





1    '       r 

r— |-ri 

1 
1 

1  ] 
!  1 

i-l. 
[i 





■ 

. 

^ 

L      _      _. 

— 1 — 1 ±^ 

I"! 1 

1 1 

■ ^ 

■  --- 

<• 

' 

1 
1 
1 

1 
1 

1 
1 

1 
i. 

* 

"■           " 

1  1 

y 

■■■    ■ 

1 

1 

a3XI^J;:3i:r^"^^3>                              \T      7"*^'             H 

--Ti"---r^ 

L &-0'- 

Zl 

14- 


Flff.   264.     Side  elevation  of  the  house  shown  In  Fig.  263. 


418 


AGRICULTURAL  ENGINEERING 


prefer  a  cloth  covering  for  the  windows  in  place  of  window 

glass. 

This  type  of  house  is  generally  built  on  skids  or  runners, 

which  facilitate  its  moving  from  one  location  to  another. 

These  runners  may  best  be  made  of  4  x  6  pieces,  although 

2x6  pieces  are  quite  often  used.     Reinforced  concrete  skids 

have  been  used  successfully  for  portable  houses  and  have  the 

advantage  of  being  free  from  decay. 

Shed-roof   House.    The   shed-roof   house   takes   more 

material  than  any  other  shape,  and  is  not  generally  made. 

The  floor,  sides,  ends,  and  roof  may  be  so  made  as  to  be  taken 

apart  for  moving.     Such  construction  might  be  an  advantage 

where  the  house  is  to  be 
moved  a  long  distance; 
otherwise  the  use  of  skids 
would  be  far  more  conven- 
ient. 

Gable-roof  House.  The 
gable-roof  portable  house 
has  many  advantages,  the 
principal   one   being    the 


7^7/3  3«fe  aTroc/' 
in  ttvo  sections 


lODoraT/'fa- 


JSr^oi  Vr£Mr 


Fig.    265. 


End    elevation    of    gable-roof    COnvemCUCe  of  haVlUg  Cer- 
colony   hog   house.  ,     .  ,.  „    ,■,  <• 

tam  sections  of  the  roof 
arranged  for  opening  during  mild  weather  and  allowing  the 
direct  sunlight  to  enter.  This  can  be  done  more  effectually 
when  the  house  is  located  east  and  west  and  a  section  of  the 
south  half  of  the  roof  is  made  to  open.  One  or  both  of  the 
sides  may  also  be  placed  on  hinges  to  open  during  warm 
weather. 

This  house  is  built  on  skids,  and  should  be  provided  with 
the  wiiidow  and  burlap  curtain  like  the  A  type  of  house. 


FARM  STRUCTURES 


419 


THE  LARGE  OR  CONCENTRATED  HOG  HOUSE 

Large  hog  houses,  as  distinguished  from  the  colony  house, 
vary  largely  in  the  arrangement  of  the  windows,  or  the  natural 
lighting.  The  value  of  direct  sunlight  in  the  hog  house  is 
generally  appreciated. 

Construction.  Houses  are  usually  located  so  as  to  extend 
east  and  west,  and  when  so  located  should  have  the  half- 
monitor  or  saw-tooth  type  of  roof.  The  windows  of  this  type 
are  so  arranged  that  those  in  the  lower  row  permit  the  sun 
to  shine  into  the  first  row  of  pens,  and  the  upper  row  into 
the  row  of  pens  on  the  north  side  of  the  building.     Hog 


Fig.   266.     A  floor  plan  of  a  large  hog  house. 

houses  built  to  extend  north  and  south  usually  have  gable 
roofs,  and  a  row  of  windows  on  each  side. 

There  is  much  difference  of  opinion  in  regard  to  the  rela- 
tive merits  of  these  two  types  of  roofs.  It  is  safe  to  say  that 
either  will  prove  entirely  satisfactory  when  properly  con- 
structed. 

The  half-monitor  roof  requires  more  material  than  the 
gable-roof  house.  The  upper  part  of  the  building  is  solely 
for  the  purpose  of  letting  sunlight  into  the  back  pens.  Such 
construction  prevents  the  proper  control  of  the  temperature, 
as  there  is  a  large  pocket  above  into  which  the  warm  air  may 
lodge.  The  back  rows  of  pens  with  this  construction  are 
shaded  more  or  less  throughout  the  entire  year.     The  open- 


420 


AGRICULTURAL  ENGINEERING 


ings  on  the  north  side  of  the  building  are  criticised  severely  by 
some  as  being  highly  undesirable.  On  the  other  hand,  the 
principal  redeeming  feature  of  this  type  of  house  is  that  the 
windows  may  be  placed  so  as  to  do  the  most  good. 

The  half-monitor  roof  is  usually  built  about  24  or  30  feet 
wide.  It  is  desirable  that  the  alley-way  be  8  feet  wide,  to 
permit  a  team  and  wagon  to  be  driven  through  the  house  when 
desired.    The  pens  at  either  side  may  be  from  8  to  12  feet 


Figr.  267.     A  cross  section  of  a  hog  house  with  half  monitor  roof.  This 
is  located  so  as  to  extend  east  and  west. 

deep  and  about  8  feet  wide.     Fig.  267  shows  a  cross-section 
of  a  house  with  the  windows  well  arranged. 

A  cross-section  of  a  gable-roof  hog  house  is  shown  in  Fig. 
278.  The  sunlight  enters  the  east  windows  early  in  the  morn- 
ing and  travels  across  the  floor,  as  the  sun  rises  higher,  until 
nearly  noon,  when  it  is  excluded  until  it  begins  to  shine  in 
through  the  west  windows.  It  is  to  be  noticed  that  this  type 
of  house  uses  less  material  than  the  first,  owing  to  the  fact  that 
there  is  not  so  much  space  in  the  upper  part  of  the  house. 


FARM  STRUCTURES 


421 


The  lighting  of  this  type  of  house  is  sometimes  augmented 
by  building  a  monitor  above  the  alley-way  and  suppljdng  two 
additional  rows  of  windows.    This  construction  adds  con- 


Fig.  268.     Cross  section  of  a  hog  house  with  gable  roof. 


siderably  to  the  cost.  A  type  of  house  which  is  being  used 
and  developed  in  Iowa  is  one  with  a  skylight  running  through- 
out the  entire  length  of  the  building.     This  system  of  lighting 


Gracry-  Kouae 
Window. 


Fig.   269.     Cross  section  of  a  hog  house  with  a  sky-light  in  the  roof. 
Direct  sunlight  strikes  all  parts  of  the  floor  during  the  day. 


422  AGRICULTURAL  ENGINEERING 

is  obviously  the  best  of  all,  as  a  solid  band  of  sunlight  must 
pass  across  the  building  every  day,  striking  every  part.  With 
windows,  only  spots  of  direct  sunhght  enter  the  building,  and 
even  when  great  care  is  used  in  the  design  of  the  building  this 
hght  strikes  but  a  relatively  small  proportion  of  the  total 
floor  space.  With  this  new  type,  the  only  portion  of  the  entire 
building  not  covered  is  the  south  end,  and  windows  may  be 
provided  to  light  this  portion  thoroughly. 

The  objection  has  been  raised  that  this  skylight  would  be 
damaged  by  hail.  An  investigation  shows  that  the  loss  of 
greenhouse  glass  is  not  great,  and  it  would  be  possible  to  pro- 
tect the  glass  with  a  wire  net  if  thought  best.  This  construc- 
tion is  the  cheapest  of  all,  as  the  building  may  be  built  quite 
low  and  the  cost  of  the  sash  for  the  skylight  is  not  much 
greater  than  the  cost  of  regular  roofing  materials.  In  some 
instances  it  may  be  necessary  to  arrange  a  shade  under  the 
skylight  if  the  house  is  to  be  used  much  during  the  summer 
months. 

The  Foundation.  The  foundation  of  a  hog  house  need 
not  be  heavy.  A  6-inch  concrete  wall  or  an  8-inch  brick 
wall  will  be  found  adequate  if  placed  on  a  12-inch  footing. 
The  foundation  should  extend  below  the  frost  fine  if  the 
building  is  to  retain  its  shape  well. 

Floors.  Earth,  plank,  and  concrete  are  used  for  the  hog 
house  floors.  Earth  is  objectionable  on  account  of  the  diffi- 
culty of  cleaning  the  house  thoroughly.  Plank  is  not  desir- 
able, for  it  furnishes  a  harbor  for  rats.  Concrete  makes  a 
very  desirable  floor,  but  has  the  objection  of  being  cold. 
Many  practical  breeders  find  that  this  objection  has  little 
weight  if  the  floor  be  placed  upon  thoroughly  drained  soil  and 
the  hogs  are  provided  with  a  liberal  amount  of  bedding.  A 
portion  of  the  floor  may  be  covered  with  boards.  The  usual 
sidewalk  construction  should  be  used  for  concrete  floors. 


FARM  STRUCTURES 


423 


Fig.    270. 


A  gable-roof   hog   house  made 
of  concrete  blocks. 


Walls.  Drop  siding  upon  2x4  studding  two  feet  on 
center  is  usually  used  for  the  walls  of  the  hog  house.  In 
cold  climates  this  construction  with  a  layer  of  sheeting  and 
building  paper  between 
should  be  used.  Ship-lap 
makes  a  very  desirable 
covering  for  the  inside  of 
the  house. 

Clay  blocks  make  a 
very  good  wall,  and  are 
cheap.  No  doubt  they 
will  come  into  more  gen- 
eral use.     Concrete  walls 

are  very  desirable,  and,  where  gravel  and  sand  can  be  secured 
cheaply,  are.  much  to  be  preferred  over  less  durable  construc- 
tion. 

The  Roof.  The  usual  method  of  constructing  the  roof  is 
to  lay  shingles  or  prepared  roofing  over  sheathing  in  the  usual 
way.  When  nearly  flat  roofs  are  used,  as  with  the  half- 
monitor  types,  prepared  roofing  is  preferable. 

Partitions.  Partitions  should  be  33^  feet  high.  Solid 
partitions  are  advised  by  a  few,  as  they  keep  the  hogs  separate; 
but  open  partitions  intercept  less  light  and  when  sows  see 
one  another  and  the  attendant  they  give  little  trouble  from 
interference  or  fright.  Doors  and  troughs  should  be  arranged 
for  convenience.  The  front  partitions  may  be  arranged  to 
swing  over  the  troughs  for  handy  cleaning  and  feeding. 
Metal  partitions,  made  of  a  metal  frame  with  woven  wire 
fencing  across,  have  not  generally  proven  satisfactory.  As 
usually  made  they  are  not  stiff  enough,  and  generally  give 
trouble  from  bending  out  of  shape.  If  made  heavy,  metal 
partitions  are  quite  expensive. 


424  AGRICULTURAL  ENGINEERING 

QUESTIONS 

1.  What  are  the  essentials  of  a  good  hog  house? 

2.  Where  should  a  hog  house  be  located? 

3.  Describe  two  types  of  hog  houses. 

4.  Give  the  principal  advantages  and  disadvantages  of  each  type. 

5.  What  is  a  good  size  of  farrowing  pen? 

6.  Describe  the  following  types  of  individual  hog  houses:  the 
A-shaped,  the  shed-roof  house,  and  the  gable-roof  house. 

7.  Describe  the  arrangement  of  windows  in  the  half-monitor  and 
gable-roof  hog  houses. 

8.  Explain  bow  a  skylight  may  be  used  effectively  to  light   a 
hog  house. 

9.  Describe  the  construction  of  the  foundation,  the  floor,  the  walls, 
and  the  roof  of  a  large  hog  house. 

10.  Discuss  the  construction  and  arrangement  of  partitions  in  a 
large  hog  house. 


CHAPTER  LXVI 
POULTRY  HOUSES 

Location.  Poultry  houses  should  be  located  on  well- 
drained,  porous  soil.  Surface  drainage  is  important,  and,  if 
necessary,  it  is  always  possible  to  modify  the  surface  by 
grading.  A  gentle  slope  to  the  south  or  the  southeast  is  best. 
A  good  windbreak  is  necessary,  but  there  should  be  sufficient 
air  drainage. 

Poultry  houses  should  not  be  made  a  part  of,  or  located 
near,  other  farm  buildings  which  may  furnish  a  harbor  for 
vermin  that  will  prey  upon  the  young  fowls.  Poultry  houses 
may  be  quite  close  to  the  dwelling  house,  as  in  many  instances 
the  women  of  the  farm  have  the  care  of  the  poultry. 

Dimensions.  Modem  poultry  houses  are  usually  built 
on  the  unit  system,  that  is,  in  sections  for  each  flock  of  25  to 
100  birds.  There  has  been  much  development  of  late  years 
in  regard  to  the  amount  of  air  and  sunlight  admitted  to  the 
poultry  house ;  in  fact,  some  houses  are  now  built  with  one 
side  entirely  open  to  the  weather.  The  poultry  house  is  sel- 
dom built  wider  than  12  feet,  although  wider  buildings  may 
be  more  economical  as  far  as  space  obtained  for  material  used 
in  construction  is  concerned.  The  unit  or  section  is  usually 
16  feet  long. 

Space  for  Each  Fowl.  The  space  for  each  fowl  is  usually 
based  on  the  area  of  floor  surface  rather  than  upon  the  cubical 
space.  Four  to  six  square  feet  is  usually  allowed  for  each 
fowl.  The  breed  of  the  fowl,  the  range  or  size  of  the  lot,  the 
climate,  and  the  size  of  the  house  are  factors  to  be  taken  into 
account  in  deciding  upon  the  amount  of  space  for  each  fowl. 

425 


426 


AGRICULTURAL  ENGINEERING 


Small  birds  require  less  space,  and  the  wider  the  range  the 
less  the  space  required.  More  space  is  needed  if  close  con- 
finement is  necessary  on  account  of  the  weather;  and  if  the 
flock  is  large  each  individual  bird  will  have  more  freedom, 


Rl_an 


Fig.  271.     Plan  of  an  A-shaped  colony  poultry  house.   (la.   Exp. 
Sta.    Bui.    132.) 


requiring  less  space  per  fowl.  In  some  instances  the  floor 
space  per  fowl  has  been  reduced  to  23/^  square  feet. 

It  is  a  good  rule  to  allow  at  least  one  cubic  foot  for  each 
pound  of  Hve  weight,  or  from  5  to  20  cubic  feet  per  fowl.  If 
enough  height  be  provided  for  convenience  in  caring  for  the 
fowls,  there  will  be  plenty  of  volume. 

The  Foundation.  Poultry  houses  are  of  light  con- 
struction and  do  not  need  elaborate  or  expensive  founda- 
tions. Colony  houses  are  built  upon  skids.  It  is  well  that 
the  foundation  of  the  nonportable  houses  be  so  constructed 
as  to  exclude  rats.  If  clay  blocks  or  other  masonry  con- 
struction be  used,  the  foundation  should  extend  below  the 
frost  Une,  to  overcome  the  damage  which  might  be  done  by 


FARM  STRUCTURES 


427 


Front    elevation    of   the    house 
shown  In  Fig.   270. 


the  heaving  action  of  the  frost.     Masonry  foundations  are 
to  be  preferred  on  account  of  their  greater  durabiUty. 

Walls.  Any  wall  construction  will  be  satisfactory  so 
long  as  it  will  prevent 
drafts,  retain  the  heat, 
prevent  the  condensation 
of  moisture,  and  furnish  a 
smooth  surface  which  may 
be  entirely  freed  from  mites 
and  other  vermin.  The 
following  wall  construc- 
tions are  generally  used: 

1.  Walls  made  of  a 
single  thickness  of  boards, 
matched  or  battened. 
Usually  this  construction 
is  too  cold  for  anything  except  southern  climates.  Building 
paper  may  be  used  on  the  inside  of  the  boards  to  make  the 
walls  air-tight. 

2.  Double  wall,  same  as  above,  except  ceiled  on  the 
inside.  For  general  use  this  construction  is  fairly  warm  but 
gives  trouble  from  condensation  of  moisture. 

3.  Same  wall  as  No.  2,  but  the  space  between  the  outside 
and  inside  boards  is  filled  with  hay  or  other  insulating  mate- 
rial. This  is  a  very  warm  wall  and  gives  little  trouble  from 
condensation. 

4.  Same  as  No.  3,  except  the  inside  sheeting  is  replaced 
with  lath  and  hard  plaster.  The  latter  gives  a  finish  which 
may  be  thoroughly  disinfected  when  desired. 

5.  Masonry  walls  of  concrete  or  clay  building  blocks. 
Concrete  makes  a  good  wall  for  a  poultry  house  if  made 
double. 


428 


AGRICULTURAL  ENGINEERING 


6.  Small  houses  may  be  covered  with  prepared  roofing 
laid  over  plain  or  matched  lumber.  Such  construction  is 
warm  and  air-tight. 

Floors.  The  cheapest  floor  for  the  poultry  house  is  the 
earth  floor,  but  it  is  Hkely  to  give  trouble  from  dampness, 
and  is  dusty  and  difficult  to  keep  clean.  Clay  should  be  used 
for  the  floor  in  preference  to  a  loam  soil.  The  earth  surface 
may  be  removed  occasionally,  or  the  entire  floor  may  be 


Perspective 

NESTS 


Fig.  273.     Detail  of  nests  for  house  shown  in  Fig  270. 

replaced  with  new  earth.  Another  objection  to  the  earth 
floor  is  that  it  is  not  vermin-proof. 

Board  floors  are  quite  expensive,  not  very  desirable,  and, 
to  be  warm,  should  be  made  double,  with  a  layer  of  tar  paper 
between  the  two  layers  of  boards.  Board  floors  are  likely 
to  form  a  harbor  for  rats. 

Cement  floors  are  the  most  durable,  the  easiest  to  clean 
and  disinfect,  and  are  quite  reasonable  in  cost.     The  objec- 


FARM  STRUCTURES 


429 


tions  to  the  cement  floor  are  that  they  are  very  hard,  cold, 
and  quite  likely  to  be  damp.  A  liberal  use  of  litter  on  the 
floor  will  overcome  the  first  two  objections.  If  placed  on  well- 


Note— 

Rootts  ond    Droppinq    board  con 
b«    removed    .separately 


fe^ 


Roosts  ^^^  Dropping  Board 

Fig.  2  74.     Detail  of  roosts  and  dropping  board. 


drained  soil  or  on  a  porous  foundation  of  cinders  or  gravel  the 
floors  ought  not  to  give  any  trouble  from  dampness.  Light 
sidewalk  construction  makes  a  satisfactory  floor. 

Roofs.  The  roofs  of  poultry  houses  are  made  in  various 
shapes,  the  principal  object  sought  with  any  style  is  to  secure 
plenty  of  windows  with  the  least  material.    Although  gable 


Perspective    o^  Framing 

Piff.  275.     The  frame  of  the  house  of  Figs.   271  to  274. 


430 


AGRICULTURAL  ENGINEERING 


roofs  and  half-monitor  roofs  are  used  to  quite  an  extent,  the 
shed-roof  house,  extending  east  and  west  with  the  slope  of  the 
roof  to  the  north,  is  the  prevailing  type  in  this  country. 
This  type  of  roof  gives  an  abundance  of  room  for  windows 
or  muslin  curtains.  Where  the  house  is  made  portable  and 
is  to  be  moved  among  trees,  as  would  be  the  case  in  an 


Fig.    276.     A  photograph  of  the  house  shown  in  Figs.  271  and  275. 


orchard,  the  combination  roof  may  be  used  to  advantage. 
This  roof  is  Hke  the  shed  roof,  except  a  small  portion  is  made 
to  slope  to  the  front,  reducing  the  height  of  the  building. 

Shingles  may  be  used  for  the  roof  if  the  pitch  is  one-third 
or  greater,  and  building  paper  is  used  under  the  shingles  to 
make  the  roof  air-tight. 


FARM  STRUCTURES 


431 


Prepared  roofing  is  very  satisfactory  for  the  roofs  of  poul- 
try houses,  as  it  is  air-tight,  and  when  a  good  quahty  is  used 
its  durability  will  compare  favorably  with  shingles. 


2'x  4*  ^tuds     2-0'  Canters 


J 


2    »  4       Roc»t» 


Roosts  and  CenUf  Horse,  can  be 
removed     separotely    from   ♦hr   ^^roo 
ana   bocird 


•More. 

Cnd  door6  may  be  emiHed 
if  only  one  section  of  \he 
KouAC     »»     built. 


Jfo-O 


=L 


Curtain 


5 


Plan 


3cree> 


Window 


Fig.  277.     Plan  of  a  farm  poultry  house  with  shed   roof.      (la.   Exp. 
Sta.    Bui.    132.) 

Windows.  It  is  recommended  by  good  authority  that 
there  should  be  at  least  1  square  foot  of  window  glass  well 
placed  for  each  16  square  feet  of  floor  space.  The  tendency 
in  the  development  of  poultry-house  construction  has  been 
toward  large  glass  or  curtain  fronts  facing  the  south  to  let  in 
the  warmth  during  the  day.  The  muslin  curtains  are 
mounted  on  frames  which  permit  them  to  be  opened  and 
closed  with  ease.  The  openings  for  the  curtains  are  covered 
with  wire  cloth  or  netting. 


432 


AGRICULTURAL  ENGINEERING 


Doors.  The  doors  for  poultry  houses  are  found  to  be 
the  most  convenient  when  hung  on  double-acting  hinges. 
Doors  so  hung  can  be  pushed  open  even  if  the  hands  are  filled. 

Partitions.  The  partitions  in  continuous  houses  may  be 
made  of  boards  or  plaster.  It  is  quite  a  common  r)ractice 
to  use  poultry  netting  for  the  upper  part,  but  the  lower  part 
should  always  be  made  soUd. 

Ventilation.  Although  flues  or  the  King  system  (see 
chapter  on  ventilation)  could  be  used  to  ventilate  poultry 


Front  Elevation 


Pig.   278.     Front  elevation  accompanying  Fig.    277. 


Window  foi" 
Ovjsi  Boa 


Wr^T.i. 


houses,  ventilation  is  generally  secured  by  means  of  cloth 
fronts.  For  other  farm  buildings  this  means  of  ventilation 
has  not  proven  satisfactory,  but  has  been  successful  with 
poultry  houses. 

TjTpes.  Poultry  houses  are  constructed  after  two  plans: 
(1)  the  colony  system,  consisting  of  isolated  houses  usually 
made  portable  for  each  flock;  and  (2)  the  continuous  system, 
consisting  of  several  adjoining  units  with  pens  for  each. 


FARM  STRUCTURES 


433 


Development,  however,  has  brought  out  the  following  three 
popular  types  of  houses: 

1.  The  scratching-shed  house  is  built  in  sections  con- 
taining two  rooms,  one  for  feeding  and  scratching  and  the 
other  for  roosting  and  laying. 

2.  The  curtain-front  house,  commonly  called  the  Maine 
Station  House.  In  this  construction  the  roosting  and  laying 
room  is  in  the  rear  of  the  scratching  pen. 

3.  The  fresh  air  or  Tolman  house.  In  this  house  the 
front  and  parts  of  the  sides  are  open.     No  more  protection 


De:tail_  '^*^ 
Rersf^ective 

or  . 

Neists 

Figr.  279.     Details  of  the  nests  of  the  house  shown  in  Figs.  277,  278. 


is  secured  for  the  fowl  at  night  than  during  the  day.  This  is 
essentially  a  colony  house,  but  may  also  be  constructed  on  the 
continuous  plan. 

Nests.    The  size  of  the  nests  will  depend  on  the  size  and 
breed  of  the  birds,  but  should  be  12x12  inches  and  5  inches 


434 


AGRICULTURAL  ENGINEERING 


deep  for  Leghorns  or  small  fowls,  and  14x14x8  inches  for 
Cochins  or  Brahmas. 

Special  Features.  The  poultry  house  should  be  wind 
proof  and  free  from  drafts.  A  curtain  placed  in  front  of  the 
roosts  will  keep  fowls  warm  in  severe  weather. 

The  nests  should  be  dark,  for  hens  lay  better  in  such  nests, 
and  the  egg-eating  habit  is  prevented. 

Due  protection  against  mites  and  lice  should  be  provided 
by  making  the  house  smooth  and  free  from  cracks  on  the 
inside. 

The  nests,  roosts,  and  droppings  board  should  be  remov- 
able for  cleaning  or  spraying.  . 

The  roosts  should  be  about  23^  feet  from  the  floors,  with 
all  bars  at  the  same  height,  as  ladder  roosts  cause  the  birds  to 


Perspective 

OF- 

RoosTS 


Fig.   280.     Details  of  roosts  of  the  house  shown  in  Figs.  277  to  279. 


crowd  to  the  top  bar.  The  roosts  are  best  when  about  2 
inches  wide  and  only  the  corners  rounded,  and  rigid  enough 
to  prevent  one  bird  from  disturbing  others  on  the  same  bar. 
The  bars  ought  to  be  placed  12  to  14  inches  apart  and  8  to  12 
inches  allowed  for  each  bird. 


FARM  STRUCTURES  435 


QUESTIONS 


1.  Where  should  the  poultry  house  be  located? 

2.  How  much  space  should  be  allowed  for  each  fowl? 

3.  Describe  suitable  foundations  and  walls  for  poultry  houses. 

4.  Discuss  the  construction  of  the  poultry  house  floor. 

5.  What  are  the  common  types  of  roofs  for  poultry  houses? 

6.  What  materials  may  be  used  to  good  advantage  in  the  con- 
struction of  the  roof? 

7.  Discuss  the  management  of  windows  for  poultry  houses. 

8.  What  are  the  curtain  fronts  for  poultry  houses? 

9.  Discuss  the  arrangement  and  construction  of  doors  and  parti- 
tions. 

10.  What  is  the  usual  provision  for  ventilation  in  the  poultry  house? 

11.  Describe  the  usual  types  of  poultry  houses. 

12.  What  should  be  the  size  of  the  nests? 

13.  Discuss  some  of  the  special  features  of  poultry-house  construc- 
tion. 


CHAPTER  LXVII 
DAIRY  BARNS 

Essentials.  The  essentials  of  a  good  dairy  barn  may  be 
enumerated  as  follows: 

1.  Warmth.  Dairy  cows  cannot  be  expected  to  produce 
well  unless  comfortably  housed.  Cows  protected  from  cold 
require  less  feed. 

2.  Sanitation.  Since  dairy  products  are  used  for  human 
food  and  since  there  is  nothing  that  is  so  easily  contaminated 
with  filth  and  disease  as  milk,  the  sanitation  of  dairy  barns  is 
perhaps  the  most  important  factor  in  their  construction. 

3.  Ventilation.  In  order  that  cows  shall  produce  well 
and  remain  healthy,  they  must  be  provided  with  plenty  of 
fresh  air. 

4.  Light.  As  explained  in  another  chapter,  adequate 
natural  lighting  is  necessary  to  cope  with  disease. 

5.  Dryness.  Barns  must  be  dry;  damp  barns  breed 
disease.     Ample  drainage  must  be  provided. 

6.  Convenience  in  handling  stock  and  feed  must  be  con- 
sidered. 

7.  Box  Stalls.  The  barn  must  have  provision  for  box 
stalls,  also  pens  for  young  stock  and  the  bull,  unless  other 
provision  is  made. 

8.  Storage  room  of  sufficient  capacity  to  suit  conditions 
must  be  provided  for  feed. 

Types  of  Bams.  Dairy  barns  may  be  classified  according 
to  the  method  of  handling  the  cows  and  also  according 
to  the  height  of  the  building.  The  open  feed  room  type  of 
dairy  bam  is  arranged  to  let  the  cows  run  loose,  and  has  but 

436 


FARM  STRUCTURES 


437 


a  few  stalls  for  use  in  milking.  This  style  is  well  adapted  to 
certified  milk  production,  as  each  cow  may  be  groomed  before 
milking.  An  objection  to  this  type  of  barn  is  that  the  cows 
cannot  be  fed  individually.  It  saves  time  in  feeding,  how- 
ever, and  the  cost  of  construction  is  low. 

The  barn  with  stalls  is  the  more  common  type.  In  com- 
parison with  the  other  system  it  may  be  said  to  be  economical 
of  room  and  that  it  enables  each  cow  to  be  fed  her  proper 
ration.  The  cows  are  under  better  control,  and  it  is  easier  to 
save  and  handle  the  litter. 

Shed  or  single-story  construction  has  the  advantage  of 
being  well  lighted  and  easily  kept  clean,  but  is  not  economical 


Fig.   281.     Floor  plan  of  a  modern  dairy  barn. 

in  construction.  This  type  usually  has  a  monitor  roof,  with 
a  row  of  windows  on  each  side.  A  loft  or  storage  floor  sup- 
plies economical  space  and  enables  the  barn  to  be  kept  warm 
more  easily.  In  this  case  all  hght  must  come  from  side  win- 
dows. 

The  Foundation.  The  foundation  for  a  dairy  barn  should 
extend  below  frost  and  should  be  on  firm  soil.  The  width  of 
footing  may  vary  from  12  to  16  inches.  An  8-inch  founda- 
tion wall  of  concrete  or  hard-burned  brick  is  sufficiently 
strong;  a  wall  of  rubble  work  should  be  wider.  Sills  should 
be  12  to  15  inches  above  the  floor. 


488  AGRICULTURAL  ENGINEERING 

Walls.  It  is  essential  to  have  a  wall  dry  and  warm,  and 
smooth  on  the  inside.  Drop  siding  is  often  used  on  the  out- 
side of  the  studding  and  smooth  ceiling  on  the  inside.  In 
mild  climates  a  single  wall  is  satisfactory,  but  in  northern 
climates  a  double  wall  must  be  used.  A  cement-plastered 
wall  on  the  inside  is  very  suitable  from  a  sanitary  standpoint. 
In  extreme  cold  localities  the  walls  may  be  stuffed  with  hay 
or  shavings.  A  monolithic,  or  solid,  concrete  wall  is  damp, 
but  a  hollow  wall  is  very  satisfactory.  These  walls  are  made 
with  about  a  4-inch  air  space  between  a  5-inch  outer  wall  and 
a  3-inch  inner  wall,  reinforced  and  tied  together  with  iron  or 
steel  headers  or  ties. 

Windows.  Windows  should  be  placed  to  give  maximum 
light;  about  1  square  foot  of  glass  to  20  to  25  feet  of  floor 
space  is  adequate. 

Space  Required.  A  common  rule  is  to  allow  1  cubic  foot 
of  space  for  each  pound  of  live  weight  housed.  For  the  av- 
erage dairy  cow  500  to  700  cubic  feet  is  sufficient  when  there 
is  proper  ventilation.  The  stalls  should  be  from  36  to  42 
inches  wide,  for  average  conditions.  The  ceiling  is  usually 
8  feet  in  the  clear. 

Floors.  Cement  floors  are  the  most  satisfactory,  but 
are  condemned  because  they  are  cold.  But  if  dry  and  pro- 
vided with  sufficient  bedding,  they  should  be  satisfactory  in 
every  way.  They  are  by  far  the  most  sanitary.  Board  floors 
may  be  used  but  are  not  durable  and  are  more  difficult  to 
clean.     No  woodwork  should  be  imbedded  in  cement  floors. 

Cork  and  wood  blocks  are  used  to  some  extent  but  have 
not  passed  beyond  the  experimental  stage. 

The  Roof.  Shingles  or  a  high  grade  of  prepared  roofing 
may  be  used. 

Size  of  Gutter.  The  gutter  is  usually  14  or  16  inches 
wide  and  4  to  10  inches  deep.    The  bottom  may  be  level, 


FARM  STRUCTURES  .439 

crosswise,  or  sloping  to  one  side.  The  latter  is  objectionable, 
as  cows  sometimes  slip  in  a  gutter  with  a  sloping  bottom. 
The  gutter  should  have  a  slope  lengthwise  of  1/16  to  l/lO  inch 
per  foot  for  drainage. 

Facing  of  Cows.  Opinions  differ  as  to  the  advantages  of 
facing  cows  in  or  out  when  two  rows  of  stalls  are  used.  Stalls 
that  face  in  are  convenient  in  feeding,  and  the  cows  do  not 
face  the  hght,  which  is  said  to  be  injurious  to  their  eyes.  Ven- 
tilation may  also  be  more  effective.     The  opposite  system 


Fig.    282.     Interior  of  a  inodern   dairy   barn. 

gives  advantages  in  removing  the  litter  and  in  milking  and 
handling  the  cows. 

Mangers.  The  mangers  for  dairy  barns  are  made  of 
plank,  concrete,  or  sheet  steel.  Concrete  mangers  are  more 
sanitary  and  durable  than  wooden  mangers,  but  are  more 
expensive.  They  should  be  made  continuous,  with  a  drain 
at  one  end  for  cleaning.  The  back  side  of  the  manger  must 
be  from  4  to  6  inches  high,  enabling  the  cows  to  lie  down. 
Mangers  are  usually  about  3  feet  in  width  over  all.  Box 
mangers  should  be  made  removable,  to  facilitate  cleaning. 


440 


AGRICULTURAL  ENGINEERING 


Patented  mangers  may  be  purchased  which  rest  on  the  floor, 
having  no  bottoms,  and  which  may  be  raised  out  of  the  way 
for  cleaning. 

Ventilation.  (See  Chapter  LXXXIV  on  this  subject.) 
Stalls.  Stalls  for  dairy  cattle  vary  in  length  from  4  to 
5  feet,  and  in  width  from  3  to  4  feet.  The  requirements  of 
the  different  breeds  in  this  respect  vary  widely.  The  length 
refers  to  the  distance  from  the  manger  to  the  gutter.  A 
stall  4  feet  6  inches  long  and  3  feet  6  inches  wide  is  suitable 
for  average  conditions. 

Wooden  stalls  or  partitions  are  being  rapidly  displaced 
by  metal  ones.  The  modern  stall,  as  shown  in  Fig.  282,  is 
made  entirely  of  pipe  or  tubing,  with  bolted  connections. 
The  size  of  pipe  or  tubing  generally  used  has  an  outside 
diameter  of  1^  or  IJ^  inches. 


J'-  Indicates  firat/y 
watcr-pmf paper  tc 
Xeep  sl'jlf  floor  tirif. 

Litter  /I  I  ley 


Fig.  283.     Cross-section  through  stalls  in  a  modern  dairy  barn. 


Cow  Ties.  One  quite  satisfactory  method  of  securing 
cows  in  the  stalls  is  by  means  of  a  strap  around  the  neck 
snapped  to  a  ring  in  a  chain  extending  between  the  posts 
of  the  stall.  This  device  permits  of  a  reasonable  amount 
of  freedom  for  the  cow. 

The  stanchion,  however,  is  the  device  more  generally 
used,  and  the  later  models  of  swinging  stanchions  leave  little 
to  be  desired.  The  old-style  fixed  stanchions  were  too 
rigid,  but  the  present  forms  are  supported  at  the  top  and 
bottom  by  short  lengths  of  chain,  giving  greater  freedom  of 
movement  to  the  cow. 


FARM  STRUCTURES  441 

QUESTIONS 

1.  What  are  the  essential  features  of  a  good  type  of  dairy  bam? 

2.  Describe  the  various  types  of  dairy  barns  with  reference  to 
methods  of  handling  the  dairy  cows  and  the  height  of  the  building. 

3.  Discuss  the  construction  of  the  foundation  for  a  dairy  barn. 

4.  In  like  manner  discuss  the  construction  of  the  walls  and  the 
roof. 

5.  How  determine  the  proper  amount  of  window  surface? 

6.  Discuss  the  construction  of  the  floor. 

7.  How  much  space  is  required  per  cow? 

8.  What  should  be  the  size  of  the  gutter? 

9.  Discuss  the  relative  merits  of  having  two  rows  of  stalls  face  in 
or  out. 

10.  What  should  be  the  size  of  the  manger?    Discuss  its  construc- 
tion. 

11.  What  should  be  the  dimensions  of  a  stall  for  a  dairy  cow? 

12.  Describe  the  construction  of  suitable  stalls. 

13.  Describe  the  chain  cow.  tie. 

14.  What  advantages  does  the  swinging  stanchion  off  er  as  a  cow  tie? 

15.  Discuss  the  construction  of  mangers  for  the  dairy  bam. 


CHAPTER  LXVIII 


HORSE  BARNS 

Some  important  features  of  horse-barn  construction  are: 
1.  The  location  should  be  prominent,  as  it  is  one  of  the 
most  used  of  farm  buildings. 

2.  Good  surface  and  underdrainage  are  necessary. 

3.  The  barn  should  be  well  lighted. 

4.  Provision  for  sufficient  hay  and  feed  must  be  con- 
sidered. 

5.  Vehicle  storage  is  often  needed. 


Fig.    284.     Floor  plan  of  a  general  farm   barn. 

Space.  Each  horse  will  require  from  700  to  1000  cubic 
feet  of  air  space.  The  barn  must  be  20  feet  wide  for  a  single 
row  of  stalls  and  30  feet  for  a  double  row. 

The  foundation  should  be  of  stone,  concrete,  or  hard- 
burned  brick,  and  should  extend  below  frost  with  sufficient 
width  of  footing.    Piers  of  stone  and  concrete  are  often  used. 

Ceiling.  The  ceiling  of  horse  barns  should  be  at  least  8 
feet  in  the  clear. 

442 


FARM  STRUCTURES 


443 


Walls.  The  walls  of  horse  barns  need  not  be  as  warm 
as  those  for  dairy  bams.  The  single  wall  is  often  considered 
sufficient  except  in  the  most  severe  climates. 

Floors.  The  floor  may  be  of  cement  or  plank,  but  clay 
is  often  preferred  for  the  front  half  of  the  stall,  at  least.  A 
shallow,  covered  gutter  2  inches  deep  is  a  good  thing  when 
proper  drainage  can  be  provided. 

Facing.  The  horses  may  be  faced  in  or  out,  and  the 
same  conditions  apply  that  were  mentioned  under  dairy  barns. 

The  feed  alley  should  be  at  least  3  feet  wide,  and  a  width 
of  4  feet  is  desirable.  A  drive-way  should  be  8  feet  wide 
for  a  wagon  or  manure 
spreader,  and  12  feet  wide 
for  a  hayrack. 

Stalls.  Horse  stalls  are 
usually  made  of  two-inch 
lumber.  Pipe  partitions 
have  been  used  to  a  very 
limited  extent.  The  ac- 
companying sketch  shows 
a  very  satisfactory  type 
of  stall  where  simplicity 
of  construction  is  desired. 
Single  stalls  for  horses  vary 
much  in  width,  all  the  way  from  3  feet  8  inches  to  6  feet. 
Five  feet  is  considered  a  good  width.  Double  stalls  are 
usually  made  8  feet  wide.  A  good  length  of  stall  is  9  feet 
6  inches,  measured  from  the  front  of  the  manger  to  the  back 
of  the  partition.  Box  stalls  vary  from  8x10  feet  for  a  small 
stall  to  10x12  feet  for  one  of  Uberal  size.  Stall  partitions 
should  be  about  6  feet  high.  The  minimum  width  of  the 
alley  behind  the  stalls  is  about  4  feet  6  inches. 

Mangers,  etc.     Mangers  are  usually  2  feet  wide  and  3 


Fig.     285. 


A    general    farm    barn    with 
gambrel    roof. 


444 


AGRICULTURAL  ENGINEERING 


feet  6  inches  high.  The  floor  of  the  manger  should  be  about 
15  inches  above  the  floor. 

Water  troughs  should  be  provided  at  a  convenient  point. 

A  harness  room  is  essential  in  order  to  protect  the  leather 
from  stable  fumes. 

Hay  carriers  should  be  so  installed  as  to  enable  the  mow 
to  be  filled  readily. 

Ventilation.     (See  Chapter  LXXXIV.) 


6 


•Section  thru  i>cb 


Fig.    286.     Detail      of   construction    of   a   horse   stall. 


QUESTIONS 

1.  What  are  some  desirable  features  in  the  horse  barn? 

2.  How  much  space  should  be  provided  for  each  horse? 

3.  Discuss  the  construction  of  the  horse  bam  with  reference  to 
foundation,  ceiling,  walls,  and  floor. 

4.  How  wide  should  feed  alleys  be? 

6.  Discuss  the  construction  of  horse  stalls. 


CHAPTER  LXIX 
BARN  FRAMING 

Roofs.  Several  types  of  roofs  are  used  in  bam  construc- 
tion. The  hip  roof,  which  slopes  from  the  four  sides  of  the 
bam  to  a  point,  is  sometimes  used  for  small  barns.  The 
shed  roof,  which  slopes  only  one  way,  is  used  for  narrow  barns. 
The  gable  roof  slopes  in  two  directions  and  has  gables,  from 
which  it  derives  its  name.  Gable  roofs  are  quite  generally 
used  for  barns.  The  curb,  or  gambrel,  roof  is  much  like  the 
gable  roof,  except  each  side  of  the  roof  has  two  pitches. 
This  type  of  roof  is  quite  generally  used  for  barns,  and,  in 
addition  to  being  quite  rigid  when  properly  constructed,  it 
adds  to  the  capacity  of  the  haymow. 

The  Braced  or  Full  Frame.  In  this  type  of  frame  heavy 
timbers  are  used,  which  are  mortised  and  pinned  together. 
Many  barn  frames  have  been  made  after  this  style,  but  the 
cost  of  the  lumber  and  the  advantages  of  the  plank  frame 
have  caused  an  almost  complete  discontinuance  of  this  style 
of  frame.  When  now  used  it  is  a  modification  of  the  old 
form. 

The  Plank  Frame  with  Purlines.  In  this  type  of  bam  no 
attempt  is  made  to  keep  the  haymow  free  from  framework, 
and  the  long  rafters  are  supported  upon  the  purUnes  resting 
upon  posts  throughout  the  frame.  It  is  possible  to  keep  the 
mow  free  from  framework  directly  under  the  hay  carrier 
track,  and  when  so  constructed  it  should  not  be  inconvenient. 
This  type  of  a  frame  is  not  generally  popular,  but  there  can  be 
no  serious  objection  to  having  the  posts  support  the  rafters 
when  they  are  properly  placed. 

445 


446 


AGRICULTURAL  ENGINEERING 


Fig.     287.      A     model     Wing    joist     barn     frame. 


Fig.  288.     A  model  Shawver  barn  frame. 


FARM  STRUCTURES 


447 


The  Wing  Joist  Frame.  The  Wing  joist  frame  is  made 
entirely  of  2-inch  lumber.  The  frame  consists  of  bents  or 
sections  placed  at  intervals  of  10  to  16  feet.  The  wall  posts 
usually  have  five  pieces  of  2-inch  lumber  below  the  mow,  two 
of  which  are  continuous,  and  extend  to  the  plate  on  which  the 
rafters  rest.  Girders  running  across  the  barn  from  post  to 
post  are  usually  made  of  three  pieces  of  2-inch  lumber.    A 


E 


^l^^S^^F^  ^1 


8''IO'Column 
fhm  S-Z''8'3 


Pig.    289.     A  sketch    of  the    Wing   joist   barn   frame. 


diagonal  brace  is  placed  from  the  top  of  the  post  supporting 
the  plate  to  an  inside  post  to  care  for  the  thrust  of  the  rafters. 
Vertical  siding  is  usually  nailed  to  girts  on  the  outside  of 
the  posts.  Plates  for  the  rafters  are  made  of  two  pieces  of  2- 
inch  lumber  in  the  form  of  a  box.  Iron  rods  are  sometimes 
used  to  brace  the  plates,  but  wooden  braces  are  preferable. 


448 


a.GRIGULTURAL  ENGINEERING 


owing  to  the  fact  that  they  are  not  only  strong  in  tension 
but  are  stiff  and  make  a  more  rigid  structure. 

A  curb  roof  is  used,  and  the  rafters,  which  are  usually  2x6 's 
are  strengthened  at  the  curb  by  braces  of  inch  boards  or  2- 
inch  pieces  cut  to  fit  underneath.  The  rafters  are  usually 
placed  two  feet  apart  on  the  larger  barns  of  this  construction, 


Z'-iP'rid^Q 


Fig.    290.     A  sketch  of   the   Shawver  barn    frame. 

and  should  have  diagonal  braces  to  make  the  frame  more 
rigid.  The  Wing  joist  frame  is  not  adapted  to  barns  over 
40  feet  wide. 

The  Shawver  Bam  Frame.  The  Shawver  barn  frame, 
as  now  constructed,  consists  of  bents  made  up  of  2-inch  lum- 
ber and  placed  8  to  16  feet  apart,  on  which  the  wall  and  rafter 


FARM  STRUCTURES 


449 


coverings  are  placed.  The  Shawver  frame  is  quite  thor- 
oughly braced  in  every  way,  as  is  shown  by  the  accompanying 
drawing.     It  is  one  of  the  standard  forms  of  barn  frames. 

Steel  Frames.  Steel  frames  are  now  manufactm-ed  for 
barns  to  a  limited  extent.  The  frame  is  made  entirely  of 
steel  in  the  shop  ready  to  set  up.  They  are  generally  more 
expensive  than  the  wooden  frames. 

Round  Bams.  In  some  locaUties  the  round  barn  is  very 
popular.  In  general,  it  has  two  serious  objections:  (1)  It 
is  quite  difficult  to  light  a  large  round  barn  efficiently,  and 
(2)  it  is  difficult  to  ar- 
range the  bam  so  as  to 
prevent  a  considerable 
waste  of  space.  A  lar- 
ger space  can  be  enclosed, 
however,  within  the  wall 
of  the  round  bam  than 
in  any  other  type  using 
the  same  amount  of  ma- 
terial. Generally  the 
frame  for  the  round  barn 
consists  of  studding, 
spaced  about  two  feet 
apart,  on  which  wooden 
hoops  of  inch  lumber 
bent  to  the  circle  are 
nailed.     The  roof  is  conical  in  form  and  is  very  rigid 


Fig.    291. 


A  sketch   of  a  barn  frame  with 
posts  and  purlins. 


Most 


round  barns  have  a  double  pitch  to  the  roof,  with  the  rafter 
cuts  as  for  the  Wing  joist  frame. 


QUESTIONS 

1.  Discu3s  the  merits  of  shed,  gable,  and  gambrel  roofs  for  bams. 

2.  Describe  the  braced  or  full  frame  for  a  bam. 
15— 


450  AGRICULTURAL  ENGINEERING 

3.  Describe  the  construction  of  a  plank-frame  bam  with  purlines. 

4.  Describe  the  construction  of  the  Wing  joist  frame. 

5.  Describe  the  construction  of  the  Shawver  plank  frame. 

6.  What  are  the  principal  advantages  and  disadvantages  of  a  steel 
bam  frame? 

7.  What  are  the  objections  to  a  round  bam,  and  its  principal 
advantages? 

8.  Describe  the  usual  method  of  framing  a  round  bam. 


CHAPTER  LXX 
THE  FARMHOUSE 

The  purposes  of  a  farmhouse  are: 

1.  To  be  a  home,  a  meeting  place  of  the  family. 

2.  To  afford  protection. 

3.  To  house  the  various  goods  and  treasures  of  the  family. 

4.  To  provide  a  place  for  the  administration  of  the  farm. 

5.  To  adorn  the  landscape. 

In  brief,  the  farmhouse  should  represent  comfort,  con- 
venience, and  economy. 

Location.  Consideration  should  be  given  to  the  follow- 
ing features  in  the  location  of  the  farmhouse.  The  health- 
fulness  of  the  location  should  be  given  first  consideration. 
The  site  should  provide  water  and  air  drainage,  and  on  this 
account  a  hillside  slope  offers  many  advantages.  A  well 
should  be  within  reasonable  distance,  if  a  supply  of  good 
water  is  not  suppUed  by  other  means.  The  barn  should 
not  be  too  far  away.  A  suitable  place  for  a  table  garden 
should  be  near.  If  located  too  far  from  the  road,  the  house 
will  be  lonely;  if  too  near,  privacy  will  be  lost. 

Designing  the  Farmhouse.  Each  house  must  be  designed 
to  fit  particular  conditions  and  requirements.  Plenty  of 
time  should  be  used  in  preparing  the  plan.  It  is  best  to  con- 
sult a  practical  builder  or  architect.  The  preliminary  draw- 
ings should  be  drawn  to  scale  in  order  that  the  planning  may 
be  carried  on  more  intelligently.  Arrangements  should  be 
made   for  possible  improvements. 

The  Foundation.  The  foundation  should  be  made  of 
goo  d,  durable  masonry  and  should  extend  below  frost  for  about 


452  AGRICULTURAL  ENGINEERING 

33^  feet,  under  most  conditions.  A  brick  wall  8  inches  thick 
is  sufficient.  Stone  walls  are  usually  made  12  to  18  inches 
thick,  according  to  the  difficulty  of  laying  a  wall  of  less  thick- 
ness. A  concrete  wall  6  to  8  inches  thick  is  satisfactory. 
A  double  wall  is  preferable  because  it  is  much  drier.  The 
footing  of  the  wall  should  be  6  to  8  inches  wider  than  the 
wall. 

The  Cellar.  The  cellar  wall  should  extend  at  least  2  feet 
above  the  ground  line,  to  provide  window  space  for  adequate 
lighting.  Great  care  should  be  taken  to  make  the  cellar 
wall  as  dry  as  possible.  In  some  instances  it  is  necessary 
to  plaster  the  outside,  making  it  air-tight,  and  to  lay  a  drain 
tile  line  outside  the  footing.  Often  material  can  be  saved 
by  building  the  cellar  under  the  entire  house.  Such  con- 
struction is  regarded  as  the  most  sanitary,  if  the  cellar  can 
be  kept  dry. 

If  a  furnace  is  to  be  installed,  the  ceihng  should  be  suffi- 
ciently high  to  provide  room  for  the  installation  of  the  warm 
air  pipes. 

THE  PLAN 

The  Dining  Room.  The  dining  room  is  often  regarded 
as  the  center  of  the  farmhouse,  and  is  in  most  instances  used 
as  the  living  room.  When  so  used  it  should  be  large  enough 
to  contain  not  only  the  dining  table,  but  also  a  library  table 
and  a  bookcase.  The  dining  room  should  have  plenty  of 
Hght,  and  a  southern  or  western  exposure  is  preferable. 

The  Kitchen.  The  kitchen  of  the  farmhouse  ought  not 
to  be  too  large,  if  it  is  not  used  as  the  laundry.  Large 
kitchens  are  the  cause  of  unnecessary  work.  It  is  best  to 
arrange  the  kitchen  with  fixed  cupboards  and  to  provide  a 
sink  and  a  convenient  location  for  the  range. 


FARM  STRUCTURES 


45^ 


The  Pantry.  Every  modern  house  should  have  a  pantry, 
which  is  most  convenient  when  in  connection  with  both  the 
kitchen  and  the  dining  room. 

The  Sleeping  Rooms.  The  sleeping  rooms  may  be  as 
small  as  10x10  feet,  but  12x14  feet  is  preferable.  All 
sleeping  rooms  should  be  provided  with  closets. 

The  Staircase.  The  staircase  should  be  wide  and  not 
too  steep.     Winding  steps  are  to  be  avoided. 

The  Bathroom.  The  bathroom  may  be  as  small  as  6x8 
feet,  but  8x10  feet  is  regarded  as  a  good  size.    It  is  most 


Fig.   292.     First  and  second  floor   plans  of  a  farmhouse. 

convenient  for  the  installation  of  plumbing  when  located 
over  the  kitchen.  The  bathroom  should  have  an  outside 
window  for  ventilation  and  Hght. 

The  Washroom.    Although  not  usually  provided,  the 
farmhouse  should  have  a  room  where  the  men  of  the  farm 


454  AGRICULTURAL  ENGINEERING 

may  hang  their  extra  coats  and  stable  clothes.  This  room 
should  have  lavatory  facihties,  enabling  the  men  to  wash 
before   entering   the   dining  room. 

The  Laundry.  Nothing  is  more  useful  in  a  well-designed 
farmhouse  than  a  room  equipped  as  a  laundry.  When 
adequate  drainage  can  be  secured,  it  is  best  located  in  the 
basement. 

QUESTIONS 

1.  What  are  the  purposes  of  a  farmhouse? 

2.  What  are  the  requisites  of  a  good  location  for  a  farmhouse? 

3.  What  course  should  be  followed  in  designing  a  farmhouse? 

4.  Discuss  the  construction  of  the  foundation. 

5.  How  should  the  cellar  of  a  farmhouse  be  constructed? 

6.  Discuss  the  special  features  to  be  considered  in  the  planning  of 
the  dining  room.  The  kitchen.  The  pantry.  The  sleeping  rooms. 
The  bathroom.     The  washroom.     The  laundry  room. 


CHAPTER  LXXI 
CONSTRUCTING  THE  FARMHOUSE 

The  Full  Frame.  The  full  frame  corresponds  to  the  full 
frame  for  barns,  made  of  dimension  stuff,  mortised  and  pinned 
together,  and  in  which  the  wall  frames  are  raised  as  a  unit. 
This  framing  began  to  be  displaced  by  the  balloon  frame 
about  1850,  and  is  now  used  only  in  a  modified  form.  It 
resists  fire  better  than  the  balloon  frame,  but  may  not  be  any 
more  substantial. 

The  Balloon  Frame.  The  balloon  frame  is  made  of  light 
timbers,  usually  2  inches  thick  and  of  varying  widths.  The 
usual  method  of  construction  is  to  lay  the  sills,  which  may  be 
either  a  box  sill  of  two  2x8  timbers,  or  a  4x6  timber.  The 
latter  is  halved  in  splicing  at  the  angles  and  in  the  comers. 
In  the  case  of  the  box  sill,  one  piece  is  laid  on  the  wall  and 
the  other  on  edge  upon  the  first.  The  sills  support  the  first- 
floor  joists,  and  from  them,  also,  the  studs,  generally  2x4's, 
are  erected.  The  studs  are  made  double  at  the  corners  and 
at  each  side  of  the  openings  for  doors  or  windows.  They  are 
placed  16  or  12  inches  o.  c.  (apart),  the  former  being  the  usual 
spacing.  The  studs  extend  to  a  double  plate  of  two  2x4 
scantUngs.  They  may  be  extended  by  a  second  piece  placed 
end  to  end  and  spliced  with  boards  nailed  on  each  side.  The 
joists  for  the  second  floor  are  supported  by  a  girt  or  ribbon  of 
lx4-inch  boards  let  into  the  studding.  The  studding  at 
each  comer  should  have  a  lx6-inch  brace  notched  in,  or  a 
diagonal  brace  made  from  a  2x4  fitted  between  the  studs .  The 
rafters  for  the  attic  are  supported  by  the  top  plate  and  the 
joists.    A  common  practice  is  to  use  a  box  sill,  lay  the  rough 


456 


AGRICULTURAL  ENGINEERING 


flooring,  and  place  the  studding  on  a  bottom  plate  nailed  to 
the  flooring.  To  support  the  studding  well,  the  rough  floor- 
ing should  be  laid  diagonally;  otherwise  all  the  studding  on 
one  side  will  be  attached  to  one  board. 

It  is  very  diflftcult  to  prevent  a  one-and-a-half  story 
house  from  sagging,  due  to  the  thrust  of  the  rafters  on  the 
plate,  which  cannot  be  held  together. 

Bridging.  Bridging  consists  of  diagonal  strips,  usually 
1x3  inches  in  cross-section,  nailed  between  the  floor  joists  to 


^ 

^^M 

r 

^mH 

^^^^^^^HPP|^^^^^^^^^^^*^^^^^iBiBJBB|^^^p  ,*/«■*.  ^M 

B^'x''".'!. , 

■  ]]{ 

■l 

^PBs  li  n 

J  ,^^,,>^^-ifr'"^^ig^ 

■ 

Fig.  293.     A  concrete  block  house  representing  a  good  type  for  the  farm. 


stiffen  and  strengthen  them.  Joists  8  to  16  feet  long  should 
be  bridged  once;  those  18  to  24  feet  long,  twice.  The  floor 
should  be  leveled  as  the  bridging  is  nailed  fast.  Two  lOd 
nails  should  be  used  at  each  end  of  the  bridging  pieces. 

The  studs  should  extend  from  sill  to  plate  in  interior  walls 
the  same  as  for  outside  walls,  in  order  that  shrinkage  will 
be  uniform. 


FARM  STRUCTURES  457 

Sheathing.  It  is  advisable  to  put  sheathing  on  diago- 
nally, as  it  then  strengthens  the  frame  very  much,  and  the 
extra  cost  of  wasted  material  and  labor  is  not  great.  The 
wall  sheathing  is  best  when  made  of  matched  lumber. 

Siding.  The  siding  generally  used  is  lap  siding  or  weather 
hoarding.  White  pine  is  the  wood  generally  used  and  is 
regarded  as  very  satisfactory.  Drop  siding,  or  so-called 
patent  siding,  does  not  give  a  pleasing  effect,  although  quite 
satisfactory  in  other  respects.  Stucco  or  plastered  walls 
are  very  satisfactory  when  the  plastering  is  on  metal  lath. 

Lathing.  The  lathing  should  be  carefully  done,  insuring 
uniform  spaces  between  the  lath.  The  girder  carrying  the 
second  floor  joists  should  be  set  in  far  enough  to  enable  the 
lath  to  be  nailed  on  strips  and  permit  the  plaster  to  cUnch 
around  the  lath.  The  direction  of  lathing  should  not  be 
changed,  as  there  is  a  greater  tendency  to  crack  the  plaster 
when  shrinkage  occurs.  An  extra  2x4  should  be  used  in  each 
corner  so  that  the  lath  can  be  securely  nailed  in  place. 

The  Roof.  The  greater  the  pitch  of  the  roof  the  better,  but 
a  half  pitch  makes  a  good  roof.  Wooden  shingles  are  generally 
used,  those  of  cypress  or  red  cedar  being  regarded  as  the  best. 
One  thousand  shingles  laid  4  inches  to  the  weather  should 
cover  100  square  feet;  but  when  laid  43^  inches  to  the  weather 
shingles  will  make  a  good  roof.  There  are  250  shingles  in  a 
bale,  which  is  made  25  layers  thick  and  20  inches  wide.  Five 
shingles  should  make  a  thickness  of  two  inches.  In  laying 
the  shingles,  joints  should  be  broken  twice,  and  plenty  of 
nails  should  be  used  in  naihng  them  on.  Creosote  and  other 
stains  act  as  a  preservative,  but  painting  is  not  advisable. 
Shingles  may  be  dipped  in  oil  with  good  results,  for  which 
about  23^  gallons  of  linseed  oil  are  required  per  M. 

The  Exterior  Finish.  The  following  suggestions  in  regard 
to  the  exterior  finish  may  be  useful.     It  should  be  plain,  and 


458  AGRICULTURAL  ENGINEERING 

all  filigree  and  turned  work  should  be  avoided,  as  it  is  not 
durable.  The  cornice  should  be  broad  in  order  to  protect 
the  walls.  The  use  of  a  water  table,  with  an  edge  under  the 
siding,  insures  a  dry  wall.  Due  provision  should  be  made 
above  windows  and  doors  for  excluding  water.  Only  the 
best  paint  should  be  used,  and  perhaps  there  is  none  better 
than  pure  white  lead  and  linseed  oil  colored,  when  desired, 
with  the  proper  tints. 

Plastering.  Back  plastering  is  thought  to  be  very  bene- 
ficial in  cold,  wet  climates,  although  not  generally  used. 
Back  plastering  may  be  either  between  the  studding  or  on 
the  studding,  with  the  second  layer  of  finishing  plaster  on 
lath  nailed  to  furring  strips.  The  latter  is  regarded  as  the 
better  method,  as  there  is  a  tendency  for  cracks  to  form  from 
shrinkage  in  the  former  method.  Metal  corner  beads  should 
be  used  on  all  exposed  plastered  corners.  The  lime  for  lime 
plaster  should  be  slacked  at  least  24  hours  before  adding  hair. 
It  should  be  then  allowed  to  stand  stacked  up  at  least  ten  days 
before  using.  Lime  mortar  may  be  made  by  adding  to  each 
barrel  of  lime  3  barrels  of  sand  and  1  to  IJ^  bushels  of  hair. 

Hard  plaster  should  be  mixed  according  to  the  directions 
furnished  by  the  manufacturers.  These  plasters  give  a 
harder  wall  and  better  protection  against  moisture. 

The  first  coat  of  plaster  is  called  the  ''scratch  coat,"  the 
second  the  "brown  coat,'*  and  the  third  the  ''white''  or 
*'skim"  coat.  Sometimes  the  third  coat  is  omitted  and  the 
walls  are  left  rough  or  given  a  "float"  finish,  which  is  tinted 
with  a  calcimine  wash. 

The  Woodwork.  Dust  lines  should  be  eliminated  as  far 
as  possible,  and  for  this  reason  plain  finish  is  desirable.  The 
architraves  or  casings  may  be  mitered  or  fitted  with  blocks  at 
the  comers;  the  latter  does  not  show  the  effect  of  shrinkage  as 
badly  as  the  mitered  corners.    The  block  placed  at  the 


FARM  STRUCTURES  459 

bottom  of  the  casing  to  doors  is  called  the  plinth.     The  fol- 
lowing are  some  additional  suggestions: 

1.  Ample  head  room  should  be  provided  over  stairs. 

2.  The  sum  of  the  rise  and  tread  of  steps  should  be  about 
17J4  inches. 

3.  "Winders, "  or  triangular  steps,  should  be  avoided. 

4.  A  half  post  should  be  placed  where  the  banister  rail 
joins  the  wall. 

5.  Dimensions  of  windows  are  given  by  the  number  and 
size  of  Ughts. 

6.  All  sash  should  be  carefully  balanced.  A  good  grade 
of  cotton  cord  is  satisfactory. 

7.  The  stop  bead  should  be  fastened  with  screws  to  per- 
mit of  adjustment  and  the  removal  of  sash. 

8.  Doors  are  made  in  three  grades.  A,  B,  and  C.  Those 
of  standard  size  and  dimensions  are  known  as  stock  doors. 
Veneered  doors  are  usually  more  satisfactory  than  solid  ones. 

The  Hardware.  The  butts,  locks,  knobs,  and  escutcheon 
plates  should  be  of  good  quality.  The  usual  grades  of  hard- 
ware are  japanned  iron,  bronze  plated,  and  solid  bronze. 
Much  can  be  added  to  the  appearance  of  a  room  by  using 
artistic,  high-grade  hardware.  Loose  pin,  wrought-iron  butts 
should  be  used,  as  they  are  stronger  than  cast-metal  butts. 
Mortise  locks  are  to  be  preferred  over  rim  locks.  Hinges 
should  be  of  ample  size  and  should  permit  the  door  to  swing 
back  against  a  stop  on  the  wall. 

The  Finishing  Woodwork.  All  woodwork  should  be 
sandpapered  with  the  grain  before  the  application  of  any 
finishing  material.  Nails  should  be  well  set  and  the  holes 
well  filled  with  putty. 

Two  coats  of  hard  oil  or  varnish  make  the  cheapest  but 
the  least  desirable  finish.  The  best  finish  is  five  or  six  coats 
of  shellac  rubbed  down.     A  wood  filler  may  be  used  before 


460  AGRICULTURAL  ENGINEERING 

the  first  coat.  The  final  coat  should  be  of  the  best  grade  of 
varnish.  Floors  are  usually  filled  and  varnished,  or  var- 
nished with  shellac  and  waxed. 

Woodwork  may  be  stained  with  water,  oil,  or  spirit 
stains.  Water  stains  may  go  deeper  but  do  not  preserve 
the  wood  as  well  as  oil  stains.  Spirit  stains  are  the  most 
expensive  and  must  be  carefully  applied,  as  any  lapping  shows 
badly. 

QUESTIONS 

1.  Describe  the  full  frame  for  houses. 

2.  Describe  the  balloon  frame  for  houses. 

3.  What  is  the  objection  to  a  one-and-ar-half  story  house  as  far  as 
framing  is  concerned? 

4.  Describe  bridging  and  state  its  use. 

5.  When  is  it  advisable  to  put  sheathing  on  diagonally? 

6.  What  are  the  relative  merits  of  lap  siding  and  drop  siding? 

7.  What  care  should  be  taken  in  lathing  a  house? 

8.  Describe  the  construction  and  the  materials  used  in  building  the 
roof. 

9.  What  are  some  of  the  important  features  of  the  exterior  finish 
of  a  farmhouse? 

10.  Explain  what  is  meant  by  back  plastering. 

11.  What  care  should  be  used  in  preparing  plaster? 

12.  What  does  scratch  coat,  brown  coat,  and  skim  coat  designate? 

13.  What  is  the  composition  of  lime  plaster? 

14.  What  is  a  float  finish  to  a  plastered  wall? 

15.  Discuss  some  important  features  of  the  woodwork. 

16.  What  care  should  be  used  in  selecting  the  hardware? 

17.  State  how  the  woodwork  may  be  finished. 

18.  What  are  the  relative  merits  of  the  various  kinds  of  wood  stains? 


CHAPTER  LXXTT 

THE  sn.0 

The  Location  of  the  Silo.  In  locating  a  silo,  the  matter 
of  convenience  should  be  given  first  consideration.  It  should 
be  in  direct  communication  with  the  feed  alley  in  the  barn. 
A  good  location  is  some  four  to  six  feet  from  the  bam  and 
joined  to  the  feed  alley  by  a  chute  extending  up  the  entire 
height  of  the  silo.  A  door  should  close  the  passage-way 
between  the  bam  and  the  silo;  and  if  the  space  be  made  to 
accommodate  the  silage  cart,  it  will  not  only  make  feeding 
easier  but  will  also  provide  a  good  place  for  storing  the  cart 
when  not  in  use. 

Nearly  all  types  of  modem  silos  are  best  located  outside 
of  the  barn.  As  a  rule,  the  silo  does  not  need  the  protection 
of  a  building,  and  the  barn  space  may  be  more  economically 
used  for  other  purposes.  Fm*thermore,  an  inside  silo  is 
inconvenient  to  fill,  as  it  is  difficult  to  deliver  the  fodder  to 
the  ensilage  cutter  unless  large  driveways  are  provided, 
which  again  are  not  economical.  The  odor  of  silage  is 
thought  objectionable  by  some;  but  when  the  silo  is  located 
outside  of  the  building  and  connected  with  it  only  by  a  chute, 
this  objection  is  overcome. 

The  Size  of  the  Silo.  The  modern  silo  is  round.  This 
shape  will  resist  the  bursting  pressure  of  the  silage  to  the 
best  advantage  and  permit  of  a  more  perfect  settling  of  the 
silage,  which  is  very  important.  A  round  silo  has  two  dimen- 
sions, diameter  and  height.  The  diameter  or  cross- section 
of  the  silo  should  be  determined  by  the  size  of  the  herd. 
From  13^  to  2  inches  of  silage  should  be  fed  from  the  silo 

461 


462 


AGRICULTURAL  ENGINEERING 


each  day,  after  the  silo  is  opened,  to  keep  the  silage  fresh. 
If  a  less  amount  is  fed,  a  growth  of  mold  is  quite  likely  to 
start  and  travel  downward  as  fast  as,  if  not  faster  than, 
the  rate  of  feeding. 

The  proper  height  of  the  silo  is  readily  determined  by 
the  length  of  the  feeding  season.  It  is  an  advantage,  how- 
ever, to  have  a  deep  silo.  First,  it  is  ecomonical,  as  addi- 
tional volume  is  obtained  without  adding  to  the  expense  of 
foundation  and  roof.  Secondly,  the  silage  depends  upon  the 
exclusion  of  air  for  its  preservation,  and  the  extra  weight  of 
silage  in  a  deep  silo  promotes  settling  and  assists  in  this 
direction.  Two  silos  of  medium  diameter  are  better  than 
one  large  one,  as  there  may  be  times  when  it  is  desired  to 
feed  the  silage  lightly. 

CapcLcity  of  silos,  and  the  amount  of  silage  that  should  be  fed  daily 
from  each. 


Inside 
diameter 

Height 

Capacity, 
tons 

Acres  of  corn 

of  15  tons 

per  acre 

Amount. 

to  be  fed  daily, 

pounds 

12 
12 
12 
12 

30 

32 

■  34 

36 

67 

74 
80 
87 

4.5 
5.0 

5.3 

5.8 

755 
755 
755 
755 

14 
14 
14 
14 

30 
32 
34 
36 

91 
100 
109 
118 

6.1 
6.7 

7.2 
7.9 

1030 
1030 
1030 
1030 

16 
16 
16 
16 
16 
16 

30 
32 
34 
36 
38 
40 

119 
131 
143 
155 
167 
180 

8.0 

8.7 

9.5 

10.3 

11.1 

12.0 

1340 
1340 
1340 
1340 
1340 
1340 

18 
18 
18 
18 

36 
38 
40 
42 

196 
212 
229 
246 

13.2 
14.1 
15.26 
16.4 

1700 
1700 
1700 
1700 

FARM  STRUCTURES  463 

The  iLSual  amount  of  silage  fed  per  day  to  various  classes  of  stock. 

Kind  of  stock  Daily  rations,  pounds 

Beef  cattle 

Wintering  calves  8  months  old 15  to  25 

Wintering  breeding  cows 30  to  50 

Fattening  beef  cattle,  18-22  months  old 

First  stage  of  fattening 20  to  30 

Latter  stage  of  fattening 12  to  20 

Dairy  cattle 30  to  50 

Sheep 

Wintering  breeding  sheep 3  to  5 

Fattening    lambs 2  to  3 

Fattening     sheep 3  to  4 

The  preceding  tables — which  give  the  capacity  of  some  of 
the  more  common  sizes  of  silos,  the  number  of  pounds  of 
silage  which  must  be  removed  daily  to  lower  the  surface  an 
average  of  two  inches,  and  an  average  ration  for  each  of 
various  kinds  of  farm  stock — should  provide  sufficient 
information  for  deciding  upon  the  size  of  silo  to  meet 
ordinary  requirements. 

To  explain  the  use  of  these  tables,  suppose  silage  is  to 
be  fed  to  10  head  of  dairy  cows,  8  head  of  calves,  and  40  head 
of  beef  stock,  for  200  days.  The  amount  of  silage  required 
per  day  will  be  about  as  follows: 

10  dairy  cows,  40  lbs.  each 400  lbs. 

8  calves,  20  lbs.  each 160  lbs. 

40  beef  cattle,  20  lbs.  each 800  lbs. 

Total  silage  fed  per  day 1360  lbs. 

Referring  to  the  first  table,  it  will  be  found  that  a  silo  16 
feet  in  diameter  will  furnish  1340  pounds  of  silage  when  2 
inches  is  fed  daily;  hence  36  feet,  or  216  times  2  inches,  will 
be  about  the  right  height.  Some  allowance  should  be  made 
for  settling. 

The  Essentials  of  a  Silo.  To  preserve  silage  a  silo  must 
have  impervious  walls  which  will  not  permit  air  to  enter  or 


464  AGRICULTURAL  ENGINEERING 

moisture  to  leave.  The  wall  must  be  strong* and  rigid  enough 
to  resist  the  bursting  pressure  of  the  silage,  and  sufficiently 
smooth  on  the  inside  to  permit  the  silage  to  settle  readily. 
In  addition  to  these  absolute  essentials,  there  are  many 
features  which  add  to  the  value  of  a  silo  and  which  should 
be  considered  in  its  selection.  Some  of  these  features  are 
as  follows: 

1.  It  is  highly  desirable  that  a  silo  be  as  durable  and 
permanent  as  possible.  All  parts  should  be  constructed 
of  materials  which  will  insure  a  long  term  of  service. 

2.  The  silo  should  require  a  minimum  expenditure  of 
labor  and  materials  for  maintenance.  This  refers  to  the 
adjustment  of  parts  for  shrinkage  and  expansion,  repainting, 
and  the  substitution  of  new  parts  for  those  which  have 
become  decayed  or  otherwise  useless. 

3.  The  silo  should  have  a  wall  which  will  prevent  as  far 
as  possible  the  freezing  of  silage. 

4.  The  silo  should  be  arranged  in  such  a  manner  as  to 
be  convenient  for  filling  and  for  the  removal  of  the  silage. 
This  refers  directly  to  the  construction  of  the  doors. 

5.  In  some  cases  it  is  desirable  to  have  a  silo  which  may 
be  taken  down  and  moved  from  one  location  to  another. 

6.  A  fire-proof  silo  may  have  the  further  advantage  of 
serving  as  a  fire  wall. 

7.  A  silo  should  be  sightly  and  should  add  to  the  appear- 
ance of  the  farmstead. 

8.  It  is  an  advantage  to  have  a  silo  of  simple  construc- 
tion, which  may  be  erected  with  the  minimum  of  skilled 
labor,  and  in  the  construction  of  which  there  is  little  chance 
for  expensive  mistakes. 

9.  Lastly,  the  silo  of  the  lowest  cost  per  unit  of  capacity, 
giving  due  consideration  to  the  other  features  of  merit,  is  the 
most  desirable. 


FARM  STRUCTURES 


465 


If  these  essentials  and  desirable  features  are  kept  clearly 
in  mind,  they  will  assist  in  comparing  the  various  types  of 
silos  now  in  general  use. 

WOOD  SILOS 

The  Stave  Silo.  The  commercial  stave  silo  is  in  more 
extensive  use  today,  the  country  over,  than  any  other  type. 
When  properly  made,  the  walls  are  air-and  water-tight, 
smooth  and  rigid,  insuring 
the  preservation  of  the 
silage. 

The  durability  of  the 
stave  silo  depends  largely 
upon  the  kind  and  grade 
of  the  material  used  in  its 
construction.  Redwood, 
cypress,  Oregon  fir,  tama- 
rack, and  white  and  yel- 
low pine  are  the  more 
common  kinds  of  wood 
used,  and  their  respective 
merits  and  durability  rank 
about  in  the  order  given. 

The  Plain  Stave  Silo. 
The  stave  silo  made  of 
plain  dimension  lumber, 
without  being  beveled  or 
grooved, is  not  satisfactory. 
Such  a  silo  is  certainly 
cheap,  but  is  very  unstable.  The  walls  are  not  as  tight  as 
when  the  staves  are  matched,  and  as  soon  as  there  is  a  little 
shrinkage  there  is  a  tendency  for  the  staves  to  fall  from  place 
into  the  silo,  and  then  the  whole  structure  collapses. 


Fig.   294. 


lave  silo  well  anchored. 


466  AGRICULTURAL  ENGINEERING 

Full-Length  Stave  Silos.  Full-length  staves  are  desirable, 
although  more  expensive.  If  spliced  staves  are  used,  the 
method  of  splicing  should  be  carefully  examined.  The 
ends  of  the  staves  are  fitted  together  by  a  U-shaped  tongue 
and  groove;  but  the  more  common  method  of  splicing  con- 
sists in  inserting  a  steel  spline  about  1-16  inch  thick  in  saw 
cuts  in  the  ends  of  the  staves  to  be  spHced. 

The  Foundation.  The  stave  silo  should  be  put  upon  a 
good  foundation.  The  foundation  wall  need  not  be  wide,  12 
inches  being  a  good  width,  but  it  is  well  that  it  extend  below 
the  frost  line,  or  about  23/^  to  3J^  feet.  As  the  silo  is  likely  to 
be  partly  full  during  the  coldest  weather,  the  frost  will  not 
be  deep  near  the  foundation.  Any  masonry  construction 
may  be  used  for  the  foundation,  but  concrete  is  especially 
well  adapted  to  the  purpose. 

Use  of  the  Pit.  It  is  doubtful  if  a  pit  is  advisable  with  a 
stave  silo.  The  increased  capacity  so  secured  is  economically 
obtained;  but  there  should  not  be  a  shoulder  or  bench  inside 
of  the  staves,  as  this  will  prevent  the  free  settling  of  the  silage. 
If  a  pit  is  used  to  increase  the  capacity  of  the  silo,  and  the 
foundation  wall  is  made  flush  with  the  staves  on  the  inside  at 
the  time  of  erection,  it  will  be  difficult  to  keep  the  silo  on  the 
foundation  as  shrinkage  occurs. 

Anchoring  and  Guying.  The  stave  silo  is  a  Ught  struc- 
ture and  when  empty  is  more  or  less  at  the  mercy  of  the  wind. 
To  guard  against  any  possible  damage  from  this  source,  it 
should  be  carefully  anchored  to  the  foundation  and  guyed  or 
braced  in  all  directions.  The  anchors  to  the  foundation 
should  be  at  least  four  in  number,  and  may  be  made  of  bars 
extending  into  the  masonry  and  bolted  to  the  staves  above. 
The  top  of  the  silo  should  be  carefully  braced  to  any  adjoin- 
ing buildings.  The  guy  wires  or  cables  should  run  in 
pairs  to  posts  and  buildings  in  opposite  directions.     These 


FARM  STRUCTURES  467 

guys  are  more  effective  when  extending  out  some  distance 
from  the  base  of  the  silo.  The  importance  of  this  anchoring 
and  bracing  is  urged  upon  all. 

The  Roof.  Every  silo  should  have  a  roof:  (1)  It  adds  to 
the  appearance;  (2)  it  strengthens  and  protects  the  staves; (3) 
it  is  a  big  factor  in  preventing  freezing;  (4)  it  makes  the  silo  a 
pleasanter  place  in  which  to  work.  No  attempt  should  be 
made  to  secure  ventilation;  in  fact,  an  attempt  should  be  made 
to  retain  the  warm  air  in  the  silo  as  far  as  possible.  Pre- 
pared roofing  of  good  quality  makes  a  durable  silo  roof.  It  is 
easily  fitted  to  a  conical  form. 

The  Doorway.  All  commercial  silos  at  the  present  time 
have  a  continuous  doorway,  across  which  there  are  no  obstruc- 
tions except  the  crossties.  This  type  of  doorway  offers 
certain  advantages  in  removing  the  silage,  and  is  just  as 
satisfactory  in  other  respects  as  the  individual  doorway.  In 
selecting  a  silo,  it  is  well  that  an  examination  be  made  of  the 
door-fasteners  to  see  whether  or  not  the  door  makes  a  per- 
fectly air-tight  joint  with  the  frame. 

The  Minneapolis  Silo.  The  Minneapolis  silo,  or  so- 
called  panel  silo,  is  constructed  of  pieces  of  planks  about  2 
feet  long,  matched  at  the  sides  and  beveled  at  the  ends,  set 
into  vertical  studding.  The  whole  is  then  bound  together 
by  hoops,  which  require  practically  no  adjustment,  as  there  is 
little  shrinkage  lengthwise  of  the  grain.  Defective  pieces  in 
this  silo  may  be  replaced  by  cutting  them  out,  driving  down 
the  pieces  above,  and  inserting  new  ones  at  the  top.  This 
type  of  silo  is  very  rigid  and  stable. 

MASONRY  SILOS 

The  Concrete  Silo.  Concrete  is  one  of  the  best  materials 
for  silos.  It  is  very  important  to  make  the  concrete  silo  wall 
impervious  to  air  and  water.    The  more  common  method  of 


468  AGRICULTURAL  ENGINEERING 

doing  this  is  to  treat  the  inside  of  the  wall,  as  soon  as  the 
forms  are  removed,  with  a  wash  of  pure  cement  and  water 
reduced  to  the  consistency  of  paint.  This  wash  thoroughly 
seals  the  pores  of  the  walls  and  prevents  the  loss  of  mois- 
ture and  the  admission  of  air.  A  coat  of  coal  tar  has  been  used 
with  good  results,  and  there  are  many  patented  compounds 
on  the  market  which  ought  to  be  entirely  satisfactory.  In 
several  cases  where  no  attempt  was  made  to  seal  the  walls  the 
juices  of  the  silage  apparently  accompHshed  that  result,  after 
two  or  three  fillings,  but  this  should  not  be  relied  upon. 

Reinforcement.  Another  common  mistake  is  the  lack  of 
reinforcement  or  the  improper  use  of  reinforcement.  The 
bursting  pressure  of  silage  is  considerable,  about  11  pounds 
per  square  foot  for  each  foot  of  depth,  as  an  average;  and  this 
pressure  must  be  fully  cared  for  or  the  walls  are  sure  to  crack. 

A  mixture  of  one  part  of  cement,  two  of  sand,  and  four  of 
broken  stone  or  screened  gravel  ought  to  make  a  good  silo 
wall.  If  good  natural  gravel  and  sand  are  at  hand,  a  mix- 
ture of  one  to  five  will  be  satisfactory. 

The  Block  Silo.  There  are  two  methods  of  using  con- 
crete: (1)  in  the  form  of  blocks,  which  are  made  and  cured 
before  being  laid  in  the  wall;  (2)  the  monolithic  wall,  require- 
ing  the  use  of  forms.  The  first  method  involves  a  large 
amount  of  labor  in  making  and  handling  the  blocks  and  lay- 
ing them  in  the  silo  wall.  So  much  labor  is  involved  that 
it  is  likely  to  be  the  most  expensive  item  of  the  entire  cost. 
The  use  of  forms  in  the  monolithic  construction  dispenses 
with  a  large  part  of  the  labor,  but  in  turn  offers  some  serious 
disadvantages.  To  obtain  good,  smooth  walls,  rather 
expensive  forms  must  be  made;  and  as  the  silo  reaches  some 
height,  the  forms  are  difficult  to  handle  without  expensive 
scaffolding  and  hoisting  apparatus. 


FARM  STRUCTURE 


469 


Monolithic  Silos.  The  solid  wall  does  not  offer  serious 
objections  in  permitting  the  freezing  of  the  silage,  especially 
if  provided  with  a  good, 
tight  roof.  The  concrete 
silo  blocks  are  nearly  al- 
ways made  to  contain  an 
air  space,  and  double  forms 
may  be  used  in  the  mon- 
olithic construction,  mak- 
ing a  double  wall.  When 
air  circulation  is  restricted 
in  the  dead-air  space  by 
horizontal  partitions  about 
every  three  feet  of  height, 
the  double  wall  is  perhaps 
the  most  satisfactory,  as 
far  as  frost-proof  qualities 
are  concerned. 

The  cost  of  a  concrete 
silo  will  depend  largely 
upon  local  conditions.  The 
cost  of  sand,  gravel,  and 
labor  are  the  deciding  factors.  Under  usual  conditions,  the 
cost  should  not  greatly  exceed  the  cost  of  a  first-class  wood- 
en silo.  No  attempt  will  be  made  here  to  discuss  the  con- 
struction of  forms. 

The  Hollow  Clay  Block,  or  Iowa  Silo.  In  general,  this 
silo  consists  of  a  wall  of  vitrified  clay  building  blocks  reinforced 
with  steel  laid  in  the  mortar  joints.  The  roof  is  made  of 
concrete,  and  the  silo  has  a  reinforced  concrete  door  frame. 

Description  of  the  Blocks.  The  blocks  are  hard-burned 
building  blocks,  and  may  now  be  had  curved  to  the  curvature 
of  the  silo  wall,  making  a  smoother  wall  on  the  inside.    These 


[   ;  ■ 

i 

1 

^  ^^^H 

U 

Fig.    295. 


monolithic  -  silo 
Crete  roof. 


with    con- 


470 


AGRICULTURAL  ENGINEERING 


blocks  are  of  the  same  material  and  have  the  same  character- 
istics as  brick;  in  fact,  in  certain  localities  they  are  called 

hollow  brick.  If  these 
blocks  are  of  good  mate- 
rial and  hard-burned  they 
are  very  durable. 

The  4x8xl2-inch  block 
has  proven  to  be  a  very 
satisfactory  size.  Larger 
blocks  are  too  large  to 
handle  with  one  hand,  and 
smaller  ones  require  more 
labor  in  laying.  These 
blocks  are  laid  on  edge, 
making  a  four-inch  wall. 
The  Cement  Wash.  If 
curved  blocks  are  used 
and  care  is  used  in  point- 
ing and  filling  the  mortar 
joints,  the  wall  will  be  suf- 
ficiently smooth  on  the  in- 
side to  omit  the  plastering. 
To  seal  the  mortar  joints  and  make  the  whole  impervious, 
a  cement  wash  should  be  applied  before  the  mortar  becomes 
hardened. 

Reinforcement.  The .  entire  bursting  pressure  of  the 
silage  should  be  carried  by  steel  wire  imbedded  in  the  mortar 
joints.  Number  3  wire  has  been  found  to  be  a  very  satis- 
factory size.  It  is  small  enough  not  to  interfere  with  the 
laying  of  the  blocks,  and  fewer  strands  are  required  than  of 
the  smaller  sizes.  This  wire  should  be  unannealed,  and  may 
be  straightened  to  the  curvature  of  the  silo  by  drawing  it 
through  a  piece  of  pipe  bent  to  the  proper  angle. 


k ' 

i^P^^r^-S^^^BS^^K^K^ 

m 

Fig.   296.     The  Iowa  silo  made  of  hollow 
vitrified  clay  building  blocks  or  tile. 


FARM  STRUCTURES 


471 


The  Doorframe.  The  doorframe  is  continuous  with  the 
crossties,  which  are  at  least  42  inches  apart.  The  jambs  are 
simply  reinforced  concrete  beams.  The  crossties  contain 
reinforced  bars  of  equal  strength  to  the  horizontal  reinforce- 
ment in  the  wall  proper,  and  extend  back  to  each  side  into 
the  open  space  in  the 
blocks,  to  obtain  a  good 
grip  upon  the  wall.  The 
blocks  containing  the  bars 
are  completely  filled  with 
concrete.  The  bars  across 
the  doorway  are  covered 
either  by  blocks  filled  with 
concrete  or  by  concrete 
alone. 

The  Foundation.  The 
foundation  for  the  Iowa 
silo  may  be  of  any  good  masonry  construction.  It  is  im- 
portant that  the  footings  be  placed  below  the  frost  line. 
Concrete  and  hard-burned  blocks  have  been  used  with  equal 
success.  A  16-inch  footing  and  a  6-  to  8-inch  wall  are  all  that 
is  required.  The  space  inside  of  the  wall  may  be  economic- 
ally added  to  the  capacity  of  the  silo.  The  extra  expense 
involved  is  simply  that  of  throwing  out  the  earth  within 
the  foundation  walls. 

Floors.  Although  a  floor  is  not  absolutely  necessary, 
it  adds  much  to  the  convenience  of  removing  and  cleaning 
up  the  silage  at  the  finish.  Four  inches  of  concrete  will  make 
an  excellent  floor.  Paving  blocks  or  sidewalk  blocks  have 
been  lised  successfully.  A  few  floors  have  been  made  by 
laying  the  hollow  blocks  flat  and  plastering  with  cement  on 
top. 


Fig.    297.     The  wall  of  the  Iowa  silo. 


472  AGRICULTURAL  ENGINEERING 

The  Roof.  The  roof  of  the  Iowa  silo  is  constructed  of 
concrete,  making  this  part  as  durable  and  lasting  as  the  rest 
of  the  silo.  The  cornice  is  made  of  blocks  laid  flat-wise, 
and  the  center  is  made  of  two  and  one-half  to  three  inches 
of  concrete  placed  upon  a  conical  form.  The  conical  shape 
is  very  desirable  for  a  concrete  roof,  as  nearly  all  of  the 
reinforcement  may  be  confined  in  the  base  of  the  cone.  If 
thoroughly  reinforced  at  this  point,  there  is  little  opportunity 
for  failure.  A  window  must  be  provided  in  the  roof  for 
fining  the  silo. 

QUESTIONS 

1.  Where  should  the  silo  be  located? 

2.  What  are  the  factors  that  determine  its  diameter  and  height? 

3.  How  does  the  capacity  of  a  silo  vary  with  its  diameter?  How 
does  the  amount  of  material  in  the  walls  vary  with  the  diameter? 

4.  How  much  silage  should  be  fed  from  the  surface  each  day? 

5.  What  are  the  essentials  of  a  good  silo? 

6.  Discuss  the  construction  of  the  stave  silo. 

7.  Upon  what  does  the  durability  of  the  stave  silo  depend? 

8.  What  are  the  merits  of  the  plain-stave  silo? 

9.  How  are  silo  staves  spliced? 

10.  Discuss  the  construction  of  the  silo  foundation. 

11.  Can  a  silo  pit  be  used  to  increase  the  capacity  of  a  stave  silo? 

12.  Describe  how  a  stave  silo  should  be  anchored  and  guyed. 

13.  Describe  two  types  of  doorways  for  silos. 

14.  Describe  the  construction  of  the  Minneapolis  or  panel  silo. 

15.  What  is  necessary  to  make  a  satisfactory  sUo  wall  of  concrete? 

16.  How  should  the  walls  be  reinforced? 

17  What  kind  of  mixture  should  be  used  in  preparing  the  concrete? 

18.  What  are  the  advantages  and  disadvantages  of  the  cement- 
block  silo? 

19.  Describe  the  monolithic  concrete  silo. 

20.  Describe  the  hollow  clay  block  or  Iowa  silo. 

21.  What  are  the  desirable  features  of  clay  blocks  for  silosr 

22.  How  may  the  wall  be  made  impervious? 

23.  How  can  the  clay-block  silo  be  carefully  reinforced? 

24.  Describe  the  construction  of  the  doorframe,  the  foundation, 
the  floor,  and  the  roof  of  the  Iowa  silo. 


CHAPTER  LXXIII 
THE  IMPLEMENT  HOUSE  AND  THE  SHOP 

The  Value  of  an  Implement  House.  It  is  not  economical 
to  have  the  machinery  stored  in  the  general  barn  or  in  any 
expensive  building.  The  implement  house  or  shed  need 
only  provide  protection  from  the  weather.  Barns  do  not 
furnish  good  storage  on  account  of  the  dust  which  must 
necessarily  be  about  and  because  of  the  inconvenience. 

The  Location.  The  best  location  for  the  implement 
house  is  that  which  makes  it  a  central  feature  of  the  farmstead 
group.  A  location  about  half-way  between  the  house  and 
barn  and  a  little  to  one  side  of  a  direct  line  between  the  two 
buildings  seems  to  be  the  most  generally  desirable.  The 
implement  house  in  this  connection  is  thought  of  as  provid- 
ing storage  for  the  farm  wagon  and  other  vehicles  used  upon 
the  farm.  Its  location  should  be  such  that  it  will  be  con- 
venient to  hitch  to  a  vehicle  or  implement  upon  coming  from 
the  bam  with  a  team  and  enable  the  driver  to  pass  as  directly 
as  possible  to  the  field  or  to  town  without  extra  travel. 

The  Size.  The  size  of  the  house  will  depend  on  the 
number  of  implements  to  be  stored.  It  is  not  best,  however, 
to  have  the  building  too  wide,  as  it  will  be  inconvenient  to 
remove  certain  implements  on  account  of  those  stored  in 
front,  which  arrangement  will  be  necessary  to  utilize  all  of 
the  space  in  a  wide  building.  In  preparing  to  build  an 
implement  shed,  it  would  be  well  to  determine  the  floor 
space  required  for  each  implement  and  then  plan  on  having 
a  certain  place  reserved  for  each.  This  arrangement  will 
save  much  time  in  handling  the  implements. 

473 


474 


AGRICULTURAL  ENGINEERING 


The  Foundation.  The  foundation  need  not  be  heavy;  a 
6-inch  concrete  wall  will  be  ample  if  it  be  widened  to  8 
to  12  inches  for  the  footing.  Piers  are  very  satisfactory  for  a 
frame  building.  If  the  walls  of  the  house  are  to  be  of  masonry 
construction,  the  foundation  should -extend  below  the  frost 
hne. 

The  Floor.  A  dry  earth  floor  is  customary  in  the  imple- 
ment house.     A  wood  or  concrete  floor  in  the  carriage  or 


Fig.   298.     A  convenient  open-front  implement  house. 

automobile  room  would  be  desirable,  but  not  a  necessity. 
Concrete  is  best,  as  boards  or  planks  are  likely  to  provide  a 
harbor  for  rats  and  other  vermin. 

The  Walls.  The  walls  need  only  provide  protection 
from  the  sun,  moisture,  and  wind.  Either  drop  or  matched 
siding  or  plain  boards  with  battens  may  be  used.  The  plain 
boards,  as  usually  erected,  make  a  tighter  wall  after  they  have 
been  in  use  for  a  time,  and  they  last  longer.  Concrete  makes 
a  very  good  wall  for  an  implement  house  and  is  not  unduly 
expensive  if  the  wall  is  not  made  too  thick.  A  four-inch  wall 
is  sufficient  if  placed  upon  a  good  foundation,  and,  if  the  wall 
be  long,  it  may  be  stiffened  by  an  occasional  pilaster.  In 
like  manner  a  four-inch  brick  wall  will  be  found  to  be  quite 


FARM  STRUCTURES  475 

satisfactory.  Hollow  clay  building  blocks,  when  such  mate- 
rial of  good  quality  can  be  readily  obtained,  make  a  very 
desirable  wall  for  the  implement  house.  Blocks  are  much 
cheaper  than  brick  and  more  wall  can  be  laid  in  a  given  time. 

One  advantage  of  the  masonry  walls  is  that  they  are  more 
nearly  dust-proof  than  a  single-board  wall,  and  the  imple- 
ments they  protect  will  present  a  better  appearance  at  all 
times.  This  feature  is  of  little  advantage  except  in  the  care 
of  the  buggies  or  carriages.  If  a  good,  tight  wall  be  provided, 
it  will  not  be  necessary  to  cover  the  vehicles  with  a  cloth,  as 
is  practiced  by  many  who  take  pride  in  the  appearance  of 
their  turnouts. 

The  Roof.  The  roof  can  well  be  made  of  an  assortment 
of  materials.  Roofing  boards  with  battens  make  a  good, 
cheap  roof  for  a  narrow  building,  especially  those  with  the 
roof  sloping  one  way  only.  A  shingle  roof,  of  at  least  one- 
third  pitch  and  of  a  good  quality  of  cedar  or  cypress  shingles, 
is  quite  satisfactory,  but  is  not  nearly  as  dust-proof  as  some 
of  the  other  forms  of  construction.  A  layer  of  building  paper 
over  the  sheathing,  as  commonly  used  in  house  construc- 
tion, would  improve  it  in  this  respect.  Prepared  roofing 
makes  a  very  desirable  roof  for  an  implement  house,  as  it  is 
perfectly  tight  and  when  a  good  quality  is  used  its  durabihty 
will  compare  favorably  with  shingles.  Care  should  be 
taken  to  make  the  walls  tight  between  the  roof  and  the  plate, 
where  it  is  desired  to  have  a  dust-proof  building. 

The  Framework.  The  framing  of  an  implement  house 
is  not  difficult.  If  a  gable  roof  is  used,  2x4  rafters  placed 
two  feet  on  center  will  be  sufficient  for  a  building  16  feet  wide, 
if  given  at  least  one-third  pitch.  If  the  house  has  a  shed  roof, 
2x4  rafters  will  be  sufficient  for  a  12-foot  span  with  a  one- 
third  pitch.  A  wider  building  should  have  2x6  rafters,  if  the 
building  is  to  retain  its  shape.     If  the  house  is  to  have  a  sec- 


476 


AGRICULTURAL  ENGINEERING 


ond  floor,  and  the  joists  do  not  support  the  plate  and  prevent 
the  thrust  of  the  rafters  from  spreading  the  building,  there 
should  be  several  diagonal  braces  from  the  plate  to  the  joist. 
The  implement  house  may  be  built  with  one  side  open. 
This  is  a  convenient  arrangement,  but  does  not  keep  out  the 
dust;  and  the  chickens  of  the  farm,  if  not  confined,  will  find 
the  machinery  a  very  satisfactory  roosting  place,  much  to  the 
detriment  of  the  machinery.  If  large  doors  are  provided,  it 
4^-0 ' 


.c^yp-?is(I'?9j?cf!9rj?.^°9r^A^ 


I     I     II     I — r 


m- 


g4'e'4  ba^Q. 


Iff 


Nofe:e-e''6'&  of?e  o/?  A ,  ^Sh 
each  siOQ  of  post  ^  T 
yjes  eyory  &. 


£arth  f/oor> 


'4'6.sqpporr  axfe/fcfs 
fu///er>gfh  ofii/c/^ 


^Iron 


bo/te'-^ 


Fig.  299.     A  cross  section  of  the  house  shown  in  Fig.  298. 

will  not  be  inconvenient  to  store  the  various  machines;  in 
fact,  one  entire  side  may  be  made  up  of  doors  hung  on  a 
double  track,  half  of  them  being  on  the  outside  track  and  the 
other  half  on  the  inside  track.  This  arrangement  permits  of 
the  doors'  being  opened  at  any  point. 

It  is  often  an  advantage  to  have  a  second  floor,  to  accom- 
modate the  light  implements,  such  as  the  cultivator,  stalk 
cutter,  corn  planter,  etc.  The  implements  may  be  drawn 
up  on  a  runway  by  means  of  a  horse  and  a  rope  and  pulley. 


FARM  STRUCTURES  477 

THE  FARM  SHOP 

Utility.  From  an  extensive  investigation  on  the  life  and 
care  of  farm  machinery  in  Colorado,  it  is  reported  *  that  71.36 
per  cent  of  the  farm  machinery  on  farms  not  having  shops 
needed  repairs,  while  only  59.25  per  cent  on  farms  having 
shops  needed  repairs.  These  facts  are  taken  by  the  writer  of 
the  bulletin  to  mean  that  the  farm  shop  has  a  ''real  value 
beyond  the  occasional  emergency  job." 

It  is  well-nigh  impossible  to  maintain  the  efficiency  of  the 
farm  equipment  without  a  liberally  equipped  shop.  It  is 
not  so  much  a  matter  of  saving  a  few  dollars  by  doing  repair 
jobs,  as  it  is  a  matter  of  getting  the  work  done. 

The  Location.  The  location  of  the  farm  shop  should  be 
similar  to  that  described  for  the  implement  house;  indeed 
it  may  be  made  a  part  of  or  an  addition  to  the  implement 
house,  as  its  usefulness  is  largely  directed  toward  the  farm 
machinery.  If  a  forge  is  installed,  due  thought  should  be 
taken  of  danger  from  fire.  The  location  may  also  be  selected 
with  reference  to  any  small  stationary  engine  or  other  source 
of  power  the  farm  may  have,  so  that  the  same  power  may 
be  available  for  tools  in  the  shop. 

The  Size.  The  farm  shop  may  be  built  large  enough  to 
house  a  wagon  or  similar  implement,  or  it  may  be  just  large 
enough  to  contain  a  bench  and  tools  and  furnish  the  minimum 
amount  of  working  room.  A  shop  16  by  20  feet  will  be 
needed  to  accommodate  large  machines.  On  the  other  hand, 
a  shop  8  by  10  feet  will  house  a  bench,  a  forge,  and  an  anvil, 
and  may  be  considered  the  minimum  size  for  practical  pur- 
poses. 

Construction.  The  house  should  afford  comfortable 
quarters  for    work  during  cold  weather.     If  made  wind- 


♦BuUetin  No.  167,  Colorado  Agricultural  Experiment  Station. 


478  AGRICULTURAL  ENGINEERING 

proof,  a  stove  may  be  put  in.  If  a  forge  be  installed,  it  and 
the  anvil  should  be  placed  on  earth,  concrete,  or  some  other 
kind  of  fire-proof  floor.  The  exterior  of  the  shop  should  be 
made  to  conform  to  the  style  of  the  other  buildings  about  the 
place.  In  buying  the  equipment,  care  should  be  exercised  to 
get  good,  standard  tools  of  known  merit. 

QUESTIONS 

1.  Why  have  a  separate  implement  house  on  the  farm? 

2.  Discuss  the  best  location  for  an  implement  house. 

3.  How  may  the  size  of  the  implement  house  be  determined? 

4.  Discuss  the  construction  of  the  foundation,  the  floor,  the  walls 
and  the  roof  of  the  implement  house. 

5.  Describe  how  the  frame  of  an  implement  house  may  be  con- 
structed. 

6.  To  what  use  may  the  second  floor  of  an  implement  house  be 
put? 

7.  Why  is  a  repair  shop  needed  on  a  farm? 

8.  Where  should  the  farm  shop  be  located? 

9.  What  are  satisfactory  dimensions  for  a  farm  shop? 
10.  Discuss  the  construction  of  a  farm  shop. 

LIST  OF  REFERENCES  FOR  FARM  STRUCTURES 

Building  Trades  Handbook. 
Farm  Buildings. 

Radford's  Practical  Bam  Plans. 
Barn  Plans  and  Outbuildings. 
The  Farmstead,  I.  P.  Roberts. 
Tuthill's  Architectural  Drawing. 
Architectural  Drawing,  C.  F.  Edminster. 

Practical  Suggestions  for  Farm  Buildings,  U.  S.  Dept.  of  Agri., 
Farmers'  Bui.  126. 

College  Farm  Buildings,  Mich.  Agri.  Exp.  Sta.,  Bui.  250. 
Circular  No.  15,  Division  of  Forestry,  U.  S.  Dept.  of  Agri. 
Architects'  and  Builders'  Pocket  Book,  F.  E.  Kidder. 
Mechanics  of  Materials,  Church. 
Materials  of  Construction,  J.  B.  Johnson. 


FARM  STRUCTURES  479 

Farm  Poultry  House,  Bui.  132,  Iowa  Agr.  Exp.  Sta. 

Building  Poultry  Houses,  Cornell  Bui.  274. 

Poultry  House  Construction  and  Yarding,  Mich.  Bui.  266. 

Poultry  House  Construction,  Wisconsin  Bui.  215. 

Poultry  Architecture,  George  B.  Fisk. 

Location  and  Construction  of  Hog  Houses,  111.  Agr.  Exp.  Sta.,  Bui. 
109. 

Hog  Houses,  U.  S.  Dept.  of  Agr.,  Farmers'  Bui.  438. 

Portable  Hog  Houses,  Wis.  Agr.  Exp.  Sta.,  Bui.  153. 

Suggestions  for  the  Improvement  of  Dairy  Barns,  111.  Agr.  Exp. 
Sta.,  Cir.  95. 

Economy  of  the  Round  Dairy  Bam,  111.  Agr.  Exp.  Sta.,  Bui.  143. 

Sanitary  Cow  Stalls,  Wis.  Agr.  Exp.  Sta.,  Bui.  185. 

Plank  Frame  Bam  Construction,  John  L.  Shawver. 

Hodgson's  Low  Cost  American  Homes. 

Modem  Silo  Constmction,  la.  Agr.  Exp.  Sta.,  Bui.  100. 

The  Iowa  Silo,  la.  Agr.  Exp.  Sta.,  Bui.  117. 

Concrete  Silos,  Universal  Portland  Cement  Co. 

Specifications,   Intemational  Correspondence  School  Text. 

Ventilation,  F.  H.  King. 

King  System  of  Ventilation,  Wis.  Agr.  Exp.  Sta..  Bui.  164. 


PART  EIGHT— FARM  SANITATION 


CHAPTER  LXXIV 
THE  FARM  WATER  SUPPLY 

The  subject  of  farm  water  supply  easily  divides  itself  into 
the  following  heads,  each  of  which  will  be  discussed  in  turn : 

1.  .The  source  of  supply. 

2.  The  quantity  required. 

3.  The  pumping  plant. 

4.  The  distribution  system. 

5.  The  storage  tank  or  reservoirs. 

The  Source  of  Water  Supply.  The  first  requisite  of  a 
suitable  source  of  water  supply  is  that  it  shall  furnish  pure 
water.  It  is  fully  realized  at  the  present  time  that  one  of  the 
most  important  places  where  the  health  of  the  family  is  to 
be  guarded  is  the  water  supply,  for  so  many  diseases  are 
traceable  to  polluted  water.  It  is  not  so  essential  that  water 
be  pure  chemically  as  that  it  be  free  from  all  germs  which 
may  cause  trouble  in  the  human  system.  Water  may  con- 
tain a  considerable  percentage  of  certain  mineral  salts  and  yet 
be  quite  healthful.  On  the  other  hand,  water  may  be  quite 
free  from  all  salts  or  mineral  matter,  be  clear,  cool,  and  spark- 
Hng,  and  still  be  filled  with  deadly  typhoid  or  other  disease 
germs. 

Wells.  The  well  is  the  most  cornmon  source  of  water 
supply  for  the  farm.  Wells  are  divided  primarily  into  two 
classes,  with  reference  to  their  depth,  as  shallow  and  deep 
wells.    The  shallow  well  refers  to  those  either  dug  by  hand 

480 


FARM  SANITATION 


481 


or  bored  with  a  common  well  auger.  These  wells  are  usually 
ol'  considerable  diameter  in  order  that  there  may  be  a  reser- 
voir for  a  quantity  of  water  within  the  well  itself.  The  shallow 
well  is  the  one  most  easily  contaminated  and  is  the  one  which 
should  be  most  carefully  protected.  It  is  best  that  the  well 
be  located  at  some  distance  from  any  leaching  cesspool, 
privy,  or  manure  heaps.  It  is  difficult  to  state  just  how  far 
away,  as  some  soils  are  much  more  open  than  others  and  the 
impurities  will  travel  a  correspondingly  greater  distance 


Flgr.  300.  A  sketch  showing  hew  the  water  of  a  shallow  well  may  be- 
come contaminated  from  manure  yards  and  cesspools.  (Kansas  Exp.  Sta. 
Bui,   143.) 

through  them.  Then,  again,  drainage  lines  become  quite 
thoroughly  estabUshed  in  the  soil  in  certain  directions;  and 
if  the  well  and  a  source  of  contamination  should  happen  to  be 
placed  in  one  of  these  seepage  lines,  the  contamination  would 
take  place  at  a  much  greater  distance  than  otherwise.  It  is 
best,  however,  that  the  well,  especially  a  surface  well,  be 
located  at  least  100  feet  from  any  disease-laden  filth. 

Much  can  be  accompUshed  in  providing  protection  against 
contamination  from  the  surface:  (1)  The  curb  or  well  waii 


482  AGRICULTURAL  ENGINEERING 

should  be  made  water-tight  for  some  distance  below  the  sur- 
face; (2)  the  well  should  have  a  good,  tight  platform  or  cover; 
and  (3)  the  surface  of  the  ground  should  be  raised  about  the 
well  so  that  all  surface  drainage  will  be  away  from  the  well. 

Surface  wells  are  the  cheapest  of  all  wells.  The  cost  per 
foot,  with  curb,  varies  from  50c  for  a  12-inch  hole,  to 
over  $2  for  a  well  four  feet  across  and  walled  with  loose 
stone.  A  good  platform  cemented  over  will  cost  about  $10. 
It  might  be  mentioned  here  that  concrete  makes  an  ideal 
pump  platform  and  will  last  indefinitely.  One  slab  can  be 
made  loose  to  furnish  access  to  the  well. 

Deep  wells  are  usually  either  driven  or  drilled.  A  driven 
well  is  made  by  attaching  a  sand  point  to  a  casing,  usually  1)^ 
inches  in  diameter,  and  simply  driving  it  into  the  ground 
until  the  point  reaches  a  water-bearing  stratum  of  gravel  or 
sand.  The  sand  point  is  made  of  perforated  brass  over  an 
iron  frame,  through  which  the  water  will  readily  pass  into  the 
casing.  The  pump  cyUnder  is  made  a  part  of  the  casing,  and 
valves  are  set  at  proper  places  by  expanding  rubber  rings  to  fit 
the  casing.     Driven  wells  never  extend  through  a  rock  stratum. 

Drilled  wells  are  made  by  operating  a  drill  inside  a  casing 
which  sinks  as  the  drill  provides  the  way.  The  mud  and  chips 
of  stone  are  removed  by  pumping  a  stream  of  water  through 
the  drill  and  out  through  the  casing.  If  the  casing  is  of  small 
diameter,  about  two  inches,  with  the  cyhnder  a  part  of  it,  it 
is  called  a  tubular  well.  The  usual  diameters  for  drilled 
wells  are  6  and  8  inches.  These  diameters  permit  the  pump 
cyhnder  and  piping  to  be  entirely  independent  of  the  well 
casing.  The  usual  cost  of  tubular  wells,  with  casing,  is  $1 
to  $1.50  per  foot.  Drilled  wells  range  in  cost  up  to  $6  per 
foot  for  an  8-inch  well  drilled  in  granite  rock. 

Deep  wells  are  rightly  considered  a  better  source  of  water 
supply  than  shallow  wells,  yet  they  are  by  no  means  entirely 


FARM  SANITATION 


4S3 


free  from  contamination.  Occasionally  drainage  lines  are 
so  thoroughly  established  in  the  soil  and  through  fissures  in 
the  rock  that  the  water  of  the  deep  wells  may  be  contami- 
nated from  the  surface. 

Springs  are  sometimes  used  as  a  source  of  water  supply. 
It  is  best  that  the  spring  discharge  at  as  high  an  elevation 
as  possible  in  order  that  there  may  not  be  many  habitations 
above  it.     When  springs  furnish  water  from  some  depth,  the 


Fig.  301.     An  improved  spring  showing  how  it  may  be  protected  from 
surface  water. 


water  is  quite  sure  to  be  free  from  all  organic  matter.  In 
considering  a  spring  as  a  source  of  water  supply,  it  should  be 
definitely  known  that  a  sufficient  amount  of  water  will  be 
furnished  throughout  the  year.  Most  springs  are  irregular 
in  their  discharge  and  at  times  furnish  little  or  no  water. 

The  ideal  location  for  a  spring  is  at  an  elevation  above  the 
farmstead,  to  which  the  water  may  be  led  in  pipes  and  perhaps 
allowed  to  flow  constantly,  the  surplus  being  wasted.  If  the 
spring  is  below  the  farmstead,  yet  high  enough  to  permit  a 


484  AORICULTURAL  ENGINEERING 

waste  to  still  lower  levels,  and  if  the  flow  is  ample  a  hydraulic 
ram  or  pumping  plant  can  be  used. 

Brooks  or  running  streams  form  another  source  of  water 
supply,  but  should  be  carefully  considered  before  using.  A 
close  inspection  should  be  made  to  determine  whether  or  not 
the  stream  is  in  any  danger  of  pollution  by  surface  washing 
from  manured  fields  or  house  and  farm  yards.  River  water 
is  quite  likely  to  be  turbid  during  the  flood  season.  Streams 
flowing  through  uninhabited  or  uncultivated  upland  will  fur- 
nish water  of  the  most  desirable  character. 

Lakes  usually  furnish  water  that  is  clear  and  potable,  ow- 
ing to  the  fact  that  the  water  is  purified  by  coming  to  rest  and 
allowing  the  impurities  to  settle.  Often,  in  settled  commu- 
nities, where  the  practice  is  not  forbidden  by  law,  the  banks 
of  lakes  are  used  as  a  dumping  ground  for  all  sorts  of 
refuse.  Such  practice  prevents  the  use  of  the  water  for 
human  consumption. 

Drinking  water  obtained  from  a  stream  or  lake  should  be 
filtered.  A  box  filled  with  sand  and  gravel  or  charcoal 
through  which  the  water  must  pass  is  the  most  common  type 
of  filter  in  use. 

The  Quantity  Required.  Care  must  be  taken,  in  selecting 
a  water  supply,  to  determine  that  the  quantity  of  water 
available  will  be  suflficient  not  only  for  all  present  needs  but 
also  for  any  increased  demand  that  may  be  foreseen.  The 
daily  requirements  must  also  be  taken  into  account  when 
planning  a  reservoir  or  storage  tank. 

The  greater  part  of  the  water  consumed  on  the  farm  is 
required  by  the  live  stock  for  drinking  purposes  and  by  the 
household.  The  house  requirements  depend  largely  on 
whether  or  not  plumbing  fixtures  are  installed.  The  amount 
consumed  per  day  by  each  of  the  various  farm  animals  is 
about  as  follows:    A  horse,  7  gallons;  a  cow,  6  gallons;  a 


FARM  SANITATION  485 

hog,  3  gallons;  and  a  sheep,  less  than  3  gallons.  Dairy  cows 
giving  milk  require  additional  water  in  proportion  to  the 
amount  of  milk  given.  Where  sanitary  plumbing  is  installed, 
about  20  gallons  of  water  per  day  will  be  consumed  for  each 
person,  large  or  small,  and  for  all  purposes,  including  the 
laundry. 

QUESTIONS 

1.  Into  what  divisions  or  heads  may  the  subject  of  farm  water 
supply  be  divided? 

2.  What  are  the  principal  sources  of  water  supply  on  the  farm? 

3.  Explain  how  surface  and  deep  wells  are  dug  or  drilled  and  curbed 
or  cased. 

4.  Describe  how  the  well  should  be  protected  from  contamination. 

5.  When  may  springs,  running  water,  and  lakes  be  used  as  a  source 
of  water  supply? 

6.  How  may  the  daily  consumption  of  water  be  estimated? 

7.  Estimate  the  amount  of  water  required  on  the  home  farm. 


CHAPTER  LXXV 
THE  PUMPING  PLANT 

The  pumping  plant  for  a  farm  water  supply  consists  of 
some  form  of  motor  and  a  pump.  Although  many  pumps  are 
still  operated  by  hand,  a  modem  water  system  can  scarcely 
be  considered  complete  without  a  motor,  for  the  simple  reason 
that  man  cannot  compete  with  motors  in  the  production  of 
power.  A  specific  instance  is  on  record  where  a  gasoline 
engine  pumped  the  water  for  a  dairy  herd  at  a  cost  of  one  cent 
per  day  for  gasoline;  whereas  two  hours  of  hand  labor,  worth 
at  least  20  cents  per  hour,  were  formerly  required.  It  is  a 
waste  of  money  to  pump  by  hand  if  a  large  quantity  of  water 
is  required  daily.  The  forms  of  motors  now  in  use  for  pump- 
ing purposes  are  the  windmill,  the  gasoline  engine,  and,  in  a 
few  instances,  the  hot-air  engine  and  the  water  wheel. 

Sources  of  Power.  A  windmill  is  better  suited  by  far 
for  the  pumping  of  water  than  for  any  other  purpose.  The 
power  of  a  windmill  is  quite  limited;  yet  an  average  pump 
requires  little  power.  Furthermore,  the  power  is  quite  irreg- 
ular, but  if  a  storage  reservoir  is  used  this  undesirable  feature 
is  easily  overcome.  As  discussed  in  a  previous  lesson,  the 
cost  of  windmill  power  consists  of  the  interest  on  the  invest- 
ment, and  the  depreciation  and  maintenance. 

The  gasoline  engine  is  well  adapted  to  the  pumping  of 
water.  As  has  been  stated,  the  average  pump  requires  very 
little  power,  and  the  gasoline  engine  has  the  advantage  over 
other  heat  motors  in  that  it  is  very  economical  in  small  units. 
A  series  of  tests  made  a  few  years  ago  at  the  Iowa  State  Col- 
lege indicated  that   20  barrels  of  water  could  be  pumped 

486 


FARM  SANITATION 


487 


against  a  head  of  100  feet,  or,  in  other  words,  lifted  that  dis- 
tance, for  every  day  in  the  year,  at  a  cost  of  less  than 
five  dollars  for  gasoline.  Again, 
the  gasoUne  engine  does  not  need 
constant  attention.  If  anything 
goes  wrong,  the  engine  will  likely 
stop  without  doing  damage.  A 
float  or  other  safety  device  may 
be  connected  with  the  igniting 
system  or  fuel  supply  in  such  a 
way  as  to  stop  the  engine  when  a 
certain  height  of  water  in  the 
supply  tank  or  a  certain  pressure 
has  been  attained. 

Hot-air  engines  have  little  to 
commend  them  other  than  their 
reliability  and  safety.  Solid  fuel 
of  almost  any  kind,  as  well  as  oil 
and  gas,  may  be  used.  They  are 
not  economical  of  fuel,  but  where 
the  fuel  is  cheap  they  may  be  oper- 
ated at  a  reasonable  expense. 

Water  wheels  can  be  used  only  in 
rare  instances,  and  will  not  be  dis- 
cussed for  this  reason.  There  are, 
no  doubt,  many  places  where  they 
may  be  used  to  advantage. 

The  pump  is  as  important  a 
part  of  the  pumping  plant  as  the 
motor.  Pump  troubles  and  repairs 
are  always  very  annoying,  and  a  pump  of  good  constructio  n 
and  properly  installed  is  always  a  good  investment.  The 
amount  of  power  required  to  operate  a  pump  is  small,  as  will 
be  shown  by  the  following  table : 


Fig.  302.  A  good  type  of 
three-way  or  underground 
pump.  This  pump  is  provided 
with  a  hydraulic  cylinder  to 
throw  the  windmill  out  of 
gear  when  a  certain  pressure 
has   been  reached. 


488  AGRICULTURAL  ENGINEERING 

Pump  tests. 


No. 
test 

Kind  of  cylinder 

1 

Lift 

Gals,  per 
min. 

H.  P 

used 

Hydrau- 
lic H.  P. 

Effi- 
ciency 
percent 

2 

21^",  brass  lined 

8 

50 

5.81 

.195 

.0732 

57.0 

3 

23^',  brass  lined 

8 

100 

5.33 

.255 

.1343 

52.5 

8 

3  ",  brass  body 

8 

50 

8.01 

.21 

.1019 

48.4 

9 

3  ",  brass  body 

8 

100 

7.8 

.395 

.1965 

49.6 

26 

4",  plain  iron 

8 

50 

10.0 

.52 

.126 

21.2 

17 

4*',  plain  iron 

8 

100 

10.3 

.75 

.259 

34.7 

Important  Features  of  a  Pump.  In  selecting  a  pump,  the 
service  to  be  required  of  it  should  always  be  kept  in  mind.  If 
the  water  is  only  to  be  Hfted  from  a  shallow  well  and  deUvered 
into  a  pail  or  tank  under  the  spout,  any  common  lift  pump 
may  be  used.  A  lift  pump  is  one  in  which  no  provision  is 
made  for  forcing  or  lifting  the  water  higher  than  the  pump 
spout.  Force  pumps  have  the  pump  rod  packed,  making  it 
water-tight. 

One  of  the  most  important  parts  of  a  pump  is  the  cylinder, 
of  which  there  are  three  common  grades  on  the  market;  viz., 
plain  iron,  iron  with  brass  lining,  and  brass-body  cylinders. 
The  first  is  the  cheapest,  but  is  the  least  durable,  as  iron 
easily  corrodes.  Brass-lined  cylinders  are  quite  satisfactory, 
in  that  the  iron  supports  and  protects  the  brass,  which  is  a 
soft  metal.  Brass-body  cylinders  are  used  where  corrosion 
will  be  unusually  rapid  and  where  space  is  Umited.  Often,  in 
drilled  wells  of  small  diameter,  brass-body  cylinders  with  the 
caps  screwed  inside  of  the  barrel  instead  of  on  the  outside 
are  installed,  thus  permitting  the  use  of  a  cylinder  of  rela- 
tively large  diameter.  Brass-body  cyhnders  will  not  stand 
severe  service.  When  dented,  they  are  almost  past  repair, 
and  the  screwing  of  the  caps  to  the  thin  barrel  is  difficult,  be- 
cause little  material  is  provided  for  the  threads.     Porcelain- 


FARM  SANITATION 


4S9 


lined  cylinders  are  used  where  the  water  contains  elements 
that  corrode  iron  and  brass. 

Plungers  are  constructed  to  suit  the  lift  under  which  they 
are  to  work.  If  the  lift  has  but  a  few  feet,  one  plunger 
leather  which  expands  out  toward  the  cylinder  walls,  making 
a  water-tight  fit,  will  be  sufficient;  but  if  the  well  is  deep  or 
the  water  is  to  be  lifted  against  pressure,  as  many  as  four 
leathers  will  be  found  best. 


Pig.  303.  Some  common  types  of  pump  cylinders.  1  is  of  plain  cast 
iron,  2  is  galvanized,  3  is  porcelain  lined,  4  and  5  are  brass  lined,  and 
6  is  an  all-brass  cylinder. 


The  valves  are  another  important  part  of  a  pump. 
They  should  be  designed  to  resist  wear  and  to  require  the 
minimum  of  attention.  There  are  at  least  four  types  of 
valves  used  in  farm  pumps.  The  hinge  valve,  made  with  a 
metal  weight  on  a  leather  disk  and  attached  at  one  side,  is 
used  where  the  Hft  is  not  great.  It  is  a  simple  valve  and  the 
cheapest,  but  is  not  well  suited  for  high  pressures.  Poppet 
valves  are  those  which  lift  directly  from  the  seat,  and  are 
made  with  one  or  three  prongs  to  guide  the  valve  to  its  seat. 
These  valves  are  the  easiest  to  repair.    Ball  valves  are  used 


490  AGRICULTURAL  ENGINEERING 

where  the  water  is  likely  to  contain  sand,  as  the  seat  of  the 
ball  valve  is  usually  quite  narrow  and  the  sand  is  not  given 
an  opportunity  to  lodge  upon  it. 

The  Stock.  The  part  of  the  pump  visible  above  the  plat- 
form is  known  as  the  stock,  and  is  made  in  a  variety  of  styles. 
The  simplest  form  is  the  lift  pump,  which,  as  a  hand  pump, 
was  formerly  made  with  wooden  stocks,  but  now  cast-iron  is 
generally  used.  The  next  simplest  is  the  force  pump,  made 
after  the  plan  of  the  common  lift  pump,  with  provision  to  pre- 
vent leakage  about  the  pump  rod. 

Where  the  water  is  to  be  pumped  into  a  storage  tank  and 
the  pump  is  in  a  more  or  less  exposed  location,  a  three-way 
pump  may  be  used.  It  provides  a  valve  that  enables  the 
water  to  be  pumped  out  of  the  spout,  or  dehvered  through  an 
underground  pipe  to  the  storage  tank,  or  drawn  from  the  tank 
through  the  spout. 

In  cold  climates  a  pump  should  be  protected  against  freez- 
ing by  surrounding  the  valves  with  a  frost-proof  well  pit  and 
providing  for  the  drainage  of  the  pump  stock.  If  a  com- 
pressed air  system  of  water  storage  is  installed,  a  special 
pump  must  be  provided  which  will  pump  a  Uttle  air  with  the 
water;  or  a  separate  air  pump  must  be  used. 

QUESTIONS 

1.  Is  the  pumping  of  water  by  hand  ever  economical? 

2.  What  are  the  principal  sources  of  power  for  pumping  water? 

3.  Discuss  the  relative  merits  of  the  gasoline  engine,  the  windmill, 
and  the  hot-air  engine,  for  pumping  water. 

4.  Describe  the  difference  between  a  lift  pump  and  a  force  pump. 

5.  What  are  the  relative  merits  of  the  different  kinds  of  pump 
cylinders?    Pump  valves? 

6.  Describe  the  three-way  pump  and  its  use. 

7.  How  should  a  pump  be  protected  from  freezing? 


CHAPTER  LXXVI 
DISTRIBUTING  AND  STORING  WATER 

Water  Pipe.  After  a  consideration  of  the  source  of  sup- 
ply for  a  farm  water  system,  the  quantity  of  water  required, 
and  the  pumping  plant,  the  next  thing  to  be  considered  is  the 
distributing  system  or  piping  by  which  the  water  is  conveyed 
to  points  where  needed  and  to  the  reservoir  for  storage.  For 
farm  water  systems,  wrought-iron  or  steel  pipe  with  screwed 
joints  is  universally  used.  Cast-iron  pipe  with  leaded  joints 
is  used  for  pipes  four  inches  or  larger  in  diameter,  but  pipes 
this  large  are  seldom  required  in  connection  with  farm  sys- 
tehis.  Wrought-iron  or  steel  pipes  placed  underground 
should  always  be  galvanized  or  coated  with  asphalt  to  pro- 
tect them  from  rust.     They  are  commonly  galvanized. 

Sizes  of  Pipe.  The  two  sizes  of  pipe  in  general  use  are 
three-fourths  and  one  inch.  In  rare  instances  half-inch  pipe 
may  be  used,  but  the  flow  of  water  through  this  size  pipe  is 
very  slow,  especially  if  a  long  length  is  used.  The  friction, 
betwe^h  the  water  and  the  walls  of  the  pipe  counteracts  the 
pressure  which  causes  the  water  to  flow.  The  fallowing 
table,  taken  from  the  Cyclopedia  of  American  Agriculture, 
indicates  how  great  the  friction  is  with  small  pipe.         ""'  ^  -^^ 

Referring  to  the  table  it  is  seen  that  if  a  pump  is  deliv- 
ering four  gallons  per  minute  through  a  length  of  }/^-inch  pipe 
500  feet  long,  it  must  do  so  against  a  friction  head  or  pressure 
of  270  feet  of  water.  This  would  be  impractical.  Although 
the  table  does  not  include  ^-inch  pipe,  the  loss  of  pressure 
due  to  friction  would  he  between  the  values  given  for  3^-  and 
1-inch  pipe.     The  average  farm  pump  will  discharge  about 

491 


492 


AGRICULTURAL  ENGINEERING 


5  gallons  per  minute,  which  would  require  the  use  of  pipe  at 
least  1  inch  in  diameter  or  larger  for  mains,  and  the  smaller 
sizes  should  only  be  used  for  branches.  In  many  cases  the 
pump  is  overloaded  by  using  pipe  of  insufficient  size. 

Flow  of  water  in  pipes. 


Flow  in  gallons  per  minute 

Head  in  feet  lost  by  friction  in  each  100  foot  of  length 

14-inch  pipe. 

1-inch  pipe. 

0.5 

1.0 

2.0 

.  4.0 

10.0 

4 

7 

17 

54 

224 

.03 
.07 

1.6 

5.3 

9.3 

Piping  Systems.  There  are  two  general  types  of  under- 
ground piping  systems  on  farms.  The  first  of  these  is  known 
as  the  ''ramified'*  system,  which  consists  of  a  main  laid  in  the 
shortest  possible  fine  from  the  water  supply  to  the  farthest 
hydrant,  with  branches  extending  out  on  either  side  like 
branches  of  a  tree.  The  one  objection  to  this  arrangement 
is  that  the  water  in  the  branches  is  dead  unless  constantly  in 
use.  There  is,  however,  a  saving  in  the  cost  of  pipe,  as 
smaller  sizes  may  be  used  for  the  branches.  The  second  type 
is  known  as  the '' circulatory"  system,  in  which  the  main  pipe 
passes  to  all  hydrants  and  the  extreme  ends  are  connected,  if 
possible.  With  this  system  the  water  does  not  stagnate  in 
any  part. 

In  planning  the  distributing  system,  it  is  best  to  provide 
large  mains  if  fire  protection  is  desired.  Valves  should  be 
put  in  various  parts  so  that  a  disturbance  in  one  part  will  not 
interfere  with  the  use  of  the  rest  of  the  system.  Often  it 
can  be  arranged  to  have  the  fresh  water,  as  pumped,  pass 
through  the  house,  thus  providing  drinking  water. 


FARM  SANITATION 


493 


Water  Storage.  The  size  of  the  storage  tank  and  reser- 
voir will  depend  primarily  on  the  kind  of  power  used  for 
pumping.  It  is  customary  to  provide  in  storage  a  supply  to 
last  five  days  when  the  pumping  is  done  by  a  windmill ;  and 
when  a  gasoline  engine  is  used,  the  storage  capacity  may  be 
reduced  to  a  two-days'  supply. 

The  two  general  methods 
of  storing  water  are  by  the  use 
of  the  elevated  tank  and  the 
pressure  tank.  The  first  of 
these  depends  upon  gravity  to 
force  the  flow  of  water,  and  the 
second  uses  compressed  air. 

Towers  and  Tanks.  The 
ideal  location  for  an  elevated 
water  reservoir  is  upon  some 
natural  eminence.  If  the  emi- 
nence is  high  enough  to  justify 
it,  the  reservoir  may  be  built 
beneath  the  surface  like  a  cis- 
tern, thus  insuring  that  the 
water  will  be  kept  cool.  If 
there  is  no  natural  means  of 
securing  elevation,  the  tank 
must  be  placed  upon  a  tower 
or  in  a  building.     The  height 

of  the  tower  will  depend  upon  the  height  of  the  buildings  to 
which  the  water  is  to  be  delivered  and  upon  the  pressure 
desired.  The  tower  may  be  made  of  steel,  wood,  or  masonry. 
Masonry  tanks  are  best,  but  often  the  cost  is  prohibitive. 

A  tank  on  a  tower  is  exposed  more  or  less  to  the  weather 
and  will  give  trouble  from  freezing.  This  is  especially  true  of 
steel  tanks.    Wooden  tanks  are  preferred  over  steel  for  out- 


* 

i 

h 

s 

Fig.  304.  An  Iowa  silo  with  a 
masonry  water  supply  tank  on 
top. 


494 


AGRICULTURAL  ENGINEERING 


side  locations,  as  they  are  easier  to  erect  and  are  cheaper. 
Cypress  is  considered  one  of  the  best  woods  for  tank  construc- 
tion, and  may  be  expected  to  last  15  to  20  years. 

Tanks  are  sometimes  placed  in  or  on  buildings,  but  great 
care  should  be  taken  to  determine  whether  or  not  the  building 
is  sufficiently  strong  for  the  purpose.  Water  in  quantity  is 
very  heavy:  300  gallons  will  weigh  2,500  pounds,  to  which 
must  be  added  the  weight  of  the  tank.  Tanks  placed  in 
residences  have  often  caused  settling  of  the  framework  under- 
neath and  consequent  cracking  of  the  plastering.  In  barns 
they  can  be  supported  to  better  advantage. 

Cement  or  concrete  towers  and  tanks  are  coming  into  use 
and,  when  properly  built  and  reinforced,  there  is  no  reason 
why  they  should  not  be  economical. 

The  masonry  silo  provides  what  is  seemingly  a  good  loca- 
tion for  a  water  tank  for  a  farm  water  supply.  The  tanks 
themselves  may  be  built  of  masonry  if  properly  reinforced, 
vand  plastered  with  cement  plaster  on  the  inside.  The  bottom 
of  the  tank  can  be  easily  constructed  of  concrete,  if  built  in  a 
conical  form  and  reinforced  to  prevent  cracking  at  the  base. 

The  Air-Pressure  System.  The  pressure  tank,  or  pneu- 
matic system,  consists  of  an  air-tight  tank,  a  force  pump. 


Fig.    305.     An  air  pressure  or   pneumatic   water  supply  system. 


FARM  SANITATION 


495 


and  suitable  piping.  As  water  is  forced  in  at  the  bottom  of 
this  tank,  the  air  within  is  compressed,  thus  driving  the 
water  from  the  tank  to  any  part  of  the  system.  As  the 
effective  capacity  of  the  tank  may  be  increased  by  having 
an  initial  pressure  of  air  within  it,  and  as  the  water  con- 
tinually absorbs  a  part  of  the  air,  an  air  pump  or  a  pump 
to  supply  the  air  with  the  water  must  be  provided. 

As  the  water  is  thoroughly  protected  by  being  tightly 
inclosed,  the  tank  may  be  placed  where  a  freezing  tempera- 
ture is  not  reached.  The  cellar  is  the  usual  location.  It 
may,  however,  be  buried  in  the  ground,  which  has  the  advan- 
tage that  the  water  is  kept  at  quite  a  uniform  temperature 
throughout  the  entire  year. 

The  air  pressure  tank  for  a  water  supply  of  small  capacity 
is  very  economical  in  first  cost.  Where  the  storage  capacity  is 
large,  however,  the  cost  is  so  great  as  to  be  almost  prohibitive. 
A  ten-barrel  tank  with  a  ^^ 

water  storage  capacity  of  *' '™ 

six  barrels  will  cost  about 
$60,  and  larger  tanks  a 
correspondingly  greater 
amount. 

A  more  recent  water- 
supply  system  is  known 
as  the  Perry  pneumatic 
water-supply  system.  It 
consists  in  a  power-driven 
air  compressor,  a  storage 
tank  for  the  air  under 
pressure,  and  an  air-  Fig.  soe 
driven  water  pump  which 
pumps  the  water  as  required,  maintaining  a  pressure  upon 
the  entire  system.    There  is  no  storage  of  the  water  at  all, 


Outer  ct>Ain0 
Witt?  ocrew  ce>p^ 


Supply  Pipe 


p^S^^^SS^S^ 


QUPPIY 

Tank 


Cutoff 


below  frost  line  3 


A  satisfactory  method  of  install- 
ing exposed  hydrants. 


496  AGRICULTURAL  ENGINEERING 

other  than  that  contained  in  the  pipes.  Definite  information 
is  not  at  hand  concerning  the  cost  or  the  success  of  this  system. 
One  distinct  advantage  of  it  is  that  water  maybe  pumped  from 
as  many  supphes  as  there  are  pumps.  Thus  one  pump  may 
supply  well  water  for  drinking  purposes,  and  another  cistern 
water  for  the  bath  and  laundry. 

QUESTIONS 

1.  What  kind  of  pipe  may  be  used  in  the  distribution  system,  and 
what  are  the  merits  of  each? 

2.  What  are  the  sizes  of  pipe  generally  used  for  the  farm  water- 
supply  system? 

3.  Explain  how  the  loss  of  friction  may  be  serious  with  small  pipes. 

4.  Describe  the  ramified  and  circulatory  systems  of  water  piping. 

5.  What  provision  may  be  made  for  fire  protection,  for  repair,  and 
for  cool  drinking  water  in  the  water  supply  system? 

6.  In  what  way  does  the  amount  of  water  storage  vary  with  the 
source  of  power? 

7.  Describe  the  two  general  systems  of  storing  water. 

8.  Discuss  the  construction  of  elevated  water  supply  tanks. 

9.  What  are  the  objections  to  an  exposed  water  supply  tank? 

10.  What  care  should  be  taken  when  the  supply  tank  is  placed  in 
a  building? 

11.  Why  does  a  masonry  silo  make  a  good  tower  for  a  water  supply 
tank? 

12.  Describe  the  air  pressure  or  pneumatic  system  of  water  supply. 

13.  What  are  the  advantages  of  this  system  and  the  main  objection 
to  it? 

14.  Describe  the  Perry  system. 

15.  What  is  the  principal  advantage  of  this  system? 


CHAPTER  LXXVII 
PLUMBING  FOR  THE  COUNTRY  HOUSE 

Modern  conveniences  for  the  country  home  are  usually 
understood  to  include  sanitary  plumbing  fixtures  for  the 
bathroom  and  for  caring  for  the  wastes  of  the  household. 
The  use  of  such  fixtures  is  dependent  upon  an  adequate  water 
supply,  a  subject  which  has  been  discussed  in  the  preceding 
chapters.  There  is  nothing  which  will  do  as  much  toward 
relieving  the  housewife  of  hard  and  disagreeable  labor  as  the 
plumbing.  It  not  only  provides  additional  comfort  and  con- 
venience to  the  extent  that  when  once  used  it  is  considered 
indispensable,  but  it  also  guards  the  health  of  all  members 
of  the  household. 

Opinions  differ  widely  in  regard  to  the  details  of  construc- 
tion and  design  of  sanitary  plumbing.  In  all  cases  care  must 
be  used  that  unnecessary  expense  is  not  incurred  in  securing 
something  which  does  not  represent  quality.  As  a  rule  the 
most  simple  fixtures  are  the  most  satisfactory.  All  parts  of 
the  fixtures,  such  as  traps  and  overflows,  should  be  so  placed 
as  to  permit  of  ready  inspection. 

Plumbing  Fixtures.  In  installing  plumbing  fixtures,  con- 
solidation should  be  kept  in  mind.  The  usual  fixtures 
installed  in  a  country  home  are  a  sink  and  hot  water  appli- 
ances in  the  kitchen,  and  a  bathtub,  closet  and  lavatory  in  the 
bathroom.  If  the  bathroom  can  be  placed  above  or  adjoin- 
ing the  kitchen  the  installation  of  the  fixtures  will  be  much 
simplified  and  much  piping  saved.  The  number  of  fixtures 
which  may  be  installed  will  depend  largely  upon  whether  or 
not  the  house  is  to  have  furnace  heat.     If  the  house  is  to  be 

497 


498 


AGRICULTURAL  ENGINEERING 


l/entilcition 


W^tsrClo^t 


heated  with  stoves,  the  bathroom  can  best  be  arranged  to 
adjoin  the  kitchen,  and  the  heat  therefrom  ought  to  prevent 
the  freezing  of  the  water  in  the  pipes.     For  this  reason  the 

pipes  should  be  protected 
as  far  as  possible  from  the 
cold.  It  is  not  best,  how- 
ever, to  place  them  in  the 
wall,  as  exposed  pipes  are 
decidedly  more  convenient 
to  repair.  One  very  satis- 
factory method  of  caring 
for  the  pipes  is  to  provide 
a  conduit  with  a  removable 
cover,  which  may  be  panel- 
ed in  such  a  way  as  not  to 
detract  from  the  appear- 
ance of  the  room.  All  of 
the  fixtures  requiring 
drainage  should  be  clus- 
tered about  the  soil  pipe 
which  should  extend  from 
the  cellar  up  through  the 
building  and  out  through 
the  roof  for  ventilation. 
This  soil  pipe  is  univer- 
sally made  of  four-inch 
cast-iron  pipe  with  fittings 
inserted  at  proper  places 
to  receive  the  drainage 
from  the  various  fixtures. 
It  is  best  that  a  clean-out  plug  be  provided  at  the  bottom. 
At  a  shght  additional  cost,  hot  water  may  be  provided. 
All  that  is  required  in  addition  is  a  hot  water  or  range  tank 


Fig.    307.        A    plumbing   sj'stem    for 
two-story  house.     The  vent  pipe  may 
omitted     with     safety     in     country     rest 
dences.     (Mo,   Eng.    Exp.    Sta.   Bui.) 


be 


FARM  SANITATION  499 

and  a  water  front  for  the  kitchen  range  or  furnace,  and  the 
necessary  piping.  The  range  tank  is  galvanized  and  usually 
holds  from  30  to  60  gallons. 

The  kitchen  sink  is  one  of  the  j&xtures  which  is  well-nigh 
indispensable.  The  cast-iron  sink,  porcelain  lined  and  with 
a  roll  rim  and  a  back  piece,  is  the  most  convenient  for  clean- 
ing. The  porcelain-lined  sink  is  just  as  serviceable,  if  not 
more  so,  than  the  sohd  porcelain,  and  is  much  cheaper.  It  is 
very  difficult  to  keep  a  plain  iron  sink  clean,  and  the  advan- 
tages of  the  porcelain-lined  will  justify  its  purchase. 

A  very  satisfactory  size  for  a  kitchen  sink  is  22  by  36 
inches,  and  it  should  not  be  smaller  than  20  by  30  inches. 
Though  opinions  differ,  32  inches  is  an  average  satisfactory 
height.  One  side  may  be  conveniently  arranged  to  receive 
the  dishes  as  they  are  washed,  permitting  them  to  drain. 

Bathroom  Fixtures.  The  bathroom  ordinarily  contains 
three  fixtures;  namely,  a  bathtub,  a  lavatory,  and  a  water 
closet.  Of  recent  years  these  fixtures  have  been  greatly  im- 
proved and  cheapened  in  cost  until  a  good  grade  is  within  the 
reach  of  all.  A  serviceable  bathtub  is  one  of  cast-iron,  porce- 
lain lined  but  with  a  wide  roll  at  the  top.  Like  the  kitchen 
sink  it  should  not  have  any  woodwork  connected  with  it. 
The  best  tubs  have  all  of  the  piping,  including  the  drains  and 
overflow,  exposed.  The  standard  width  for  bathtubs  is  30 
inches,  and  they  may  be  had  in  any  length  from  4  to  6  feet. 

The  lavatory  should  be  either  solid  porcelain  or  porcelain- 
enameled  cast-iron.  To  avoid  cracks  in  which  dirt  may 
accumulate,  the  back  should  be  made  soUd  with  the  bowl. 

The  water  closet  in  general  use  is  of  solid  white  earthen- 
ware with  siphon  action.  The  cleaning  jet  should  discharge 
from  the  rim  of  the  closet  and  should  clean  thoroughly.  Two 
kinds  of  flush  tanks  are  in  general  use,  the  ''low  down"  and 
the  "high."    The  first  does  not  make  as  much  noise  when 


500  AGRICULTURAL  ENGINEERING 

flushed  as  the  second  but  generally  uses  more  water.  The 
water  is  discharged  from  the  second  with  considerable  force, 
and  for  that  reason  is  preferred  by  some. 

Back  Vents.  In  nearly  all  cities  all  fixtures  are  required 
by  law  to  have  vents  from  the  traps  to  prevent  the  water 
which  closes  the  pipe  and  prevents  the  entrance  of  foul  gases 
into  the  room  from  being  siphoned  over  into  the  sewer.  This 
system  of  piping  is  shown  in  the  accompanying  figure;  it  intro- 
duces considerable  extra  expense.  In  country  houses  there 
is  doubtless  little  danger  in  omitting  this  extra  piping. 

There  will  be  little  difficulty  in  installing  plumbing  in  a 
house  not  built  especially  for  the  purpose,  providing  there  is 
room  for  it.  There  is  some  inconvenience  in  putting  the 
pipes  in  place,  but  in  most  cases  they  can  be  left  in  exposed 
locations,  which  is  some  advantage. 

The  plumbing  referred  to  and  of  the  quahty  suggested 
will  cost  less  than  $200  almost  anywhere  in  the  Middle  West; 
in  fact,  the  average  cost  should  not  exceed  $150. 

QUESTIONS 

1.  What  are  some  of  the  general  considerations  involved  in  the 
installation  of  plumbing? 

2.  How  may  plumbing  be  arranged  in  houses  without  furnace  heat? 

3.  How  secure  convenience  in  cleaning  and  inspection? 

4.  What  are  the  usual  fixtures  required? 

5.  Discuss  the  merits  of  various  grades  of  sinks. 

6.  What  should  be  avoided  in  the  selection  of  a  lavatory? 

7.  Discuss  the  different  types  of  water  closets. 

8.  What  is  meant  by  back  venting? 

9.  How  much  should  the  plumbing  in  an  average  farmhouse  cost? 


CHAPTER  LXXVIII 
THE  SEPTIC  TANK  FOR  FARM  SEWAGE  DISPOSAL 

Modem  plumbing  fixtures  for  the  farmhouse  introduce  a 
new  problem,  the  disposal  of  the  sewage.  Present-day  ideas 
concerning  sanitation  have  made  the  privy  and  the  cesspool 
less  tolerable  than  formerly.  The  modem  sewage  disposal 
plant,  if  it  is  to  fill  its  purpose  to  the  greatest  extent,  should 
not  only  prevent  accumulation  of  sewage  to  harbor  disease 
and  contaminate  the  water  supply,  but  should  also  provide 
for  the  saving  of  fertiUzing  material  which  otherwise  would 
be  wasted. 

Disposal  of  Sewage  into  Rivers.  If  a  large  stream  of 
water  be  near,  the  sewage  may  be  discharged  into  it  in  a 
manner  similar  to  that  followed  by  the  large  cities.  The 
organic  material  contained  in  the  sewage  when  exposed  to 
the  light  and  air  as  it  passes  off  down  the  river  is  rapidly 
purified  by  bacterial  action.  Rivers  as  a  means  of  disposing 
of  the  sewage  from  farmhouses  are  rarely  available  and  will 
not  be  discussed  further. 

The  Cesspool.  While  the  cesspool  has  been  the  most 
common  method  of  disposing  of  sewage  in  isolated  places,  it 
has  but  few  features  to  commend  it  and  should  not  be  used  if 
there  is  the  least  danger  of  its  spreading  disease.  As  usually 
constructed  the  cesspool  consists  of  a  cistern  in  the  ground, 
with  an  open  wall,  usually  of  brick,  through  which  seepage 
takes  place.  In  some  open  soils  this  seepage  is  rapid,  and  no 
difficulty  is  experienced  from  the  cesspool's  overflowing  at 
times.  In  dense,  retentive  soils,  the  solid  matter  of  the  sew- 
age closes  the  porous  walls  to  the  extent  that  the  liquids  do 

501 


602  AGRICULTURAL  ENGINEERING 

not  sweep  away  fast  enough.  If  there  is  much  grease  in  the 
sewage  it  is  Ukely  to  become  hardened  over  the  surface  of  the 
walls,  makmg  them  water-tight.  To  overcome  this  difficulty 
common  lye  has  been  used  to  cut  the  grease,  with  good  success. 
All  cesspools  should  be  arranged  with  a  manhole,  which  will 
permit  the  settlings  or  solid  matter  which  collects  in  the 
bottom  to  be  removed  at  regular  intervals,  perhaps  once 
a  year. 

Many  cesspools  that  have  been  in  use  for  years  are  entirely 
satisfactory  as  far  as  observations  go.  The  success  of  these 
is  undoubtedly  due  to  the  purifying  bacterial  action  which 
the  sewage  undergoes  in  the  tank.  At  best,  however,  the 
cesspool  is  a  dangerous  means  of  disposing  of  sewage,  and 
new  installations  should  be  of  more  improved  design.  Often 
the  contamination  of  the  water  supply  is  effected  at  an  un- 
dreamed-of distance,  resulting  in  typhoid  fever,  dysentery, 
and  other  complaints. 

Principles  of  Sewage  Disposal.  The  principle  involved 
in  the  purification  of  sewage  in  the  modern  disposal  plant, 
regardless  of  whether  it  be  for  city  or  private  use,  is  largely 
that  of  destroying  the  suspended  matter  in  the  water  by 
bacterial  action.  Outside  of  this,  some  results  are  brought 
about  by  settling,  thus  caring  for  a  part  of  the  suspended 
material. 

When  the  sewage  from  a  farmhouse,  consisting  of  the  wash 
water  from  kitchen  and  dairy  and  the  discharge  from  plumb- 
ing fixtures,  is  drained  into  a  dark  reservoir  and  not  disturbed 
for  a  time,  rapid  bacterial  action  takes  place.  The  bacteria 
which  work  in  a  tank  of  this  sort  do  not  need  light  or  air  to 
live.  The  action  is  simply  this:  the  bacteria  feed  upon  the 
organic  matter  of  the  sewage  and  thereby  partially  destroy  it; 
in  addition,  a  part  of  thissohd  matter,  or  sludge,  as  it  is  called, 
is  liquified. 


FARM  SANITATION 


503 


The  reservoir  provided  for  this  purification  by  bacterial 
action  is  known  as  the  septic  tank.  To  secure  the  best 
results,  this  septic  tank  should  be  designed  to  exclude  light 
and  air  and  to  bring  the  sewage  to  rest  and  hold  it  so  for  a 
time. 

The  purification  of  ^the  sewage,  however,  is  not  completed 
in  the  septic  tank.  To  complete  the  process,  means  must 
be  provided  to  permit  another  class  of  bacteria  to  ^ct  upon 


Oi///e/ 


Fig. 


308.     A  general   view  of  a  septic  tank  arranged  to  be   connected  with 
an  underground  irrigation  or  filter  system  without  a  siphon. 
(After  Stewart.) 


the  sewage.  These  must  have  air  and  light  or  they  cannot 
live.  To  supply  the  proper  conditions  for  this  second  bac- 
terial action,  two  plans  are  followed :  the  first  is  to  provide  a 
filter  bed  of  coarse  material,  usually  gravel,  over  which  the 
sewage  from  the  septic  tank  is  discharged  at  intervals;  and 
the  second  is  to  provide  a  shallow  tile  system  from  which  per- 
colation will  take  place.  These  tile  are  usually  placed  within 
ten  to  twelve  inches  of  the  surface,  and,  if  the  soil  is  retentive, 
a  second  and  deeper  system  is  laid  to  carry  away  the  purified 
sewage.     In  some  places  this  filter  system  of  drain  tile  is  used 


504 


AGRICULTURAL  ENGINEERING 


as  a  means  of  subirrigation,  furnishing  the  growing  plants  on 
the  surface  with  moisture  and  fertihty.  It  is  to  be  noted  that 
the  discharge  into  the  filter  system  should  be  intermittent,  in 
order  that  the  bacteria  at  work  shall  not  be  drowned. 

Another  plaai  of  filtering  which  is  used  to  some  extent  is 
to  allow  the  discharge  to  trickle  down  through  a  bed  of  sand, 
which  is  placed  over  a  perforated  cover,  to  a  second  tank  in 
which  the  water  level  is  maintained  several  inches  below. 
The  dripping  of  the  sewage  through  the  air  corresponds  quite 


Fig. 


f /*»>&/  OrBn>/<en  Sfone 

309.     Section  of  a   septic  tank  made  entirely  of  concrete, 
a   siphon  and  a  filter  bed  of  sand  and  gravel. 


closely  to  the  sprinkling  system  of  sewage  disposal  which  is 
used  to  some  extent  in  city  plants. 

Size  of  Septic  Tank.  The  septic  tank  should  be  suffi- 
ciently large  to  hold  the  entire  discharge  for  about  one  day, 
in  which  case  the  best  bacterial  action  will  be  obtained. 
Another  rule  tried  out  more  or  less  by  practice  is  to  provide  20 
gallons'  capacity  for  each  person  in  the  household.  There  will 
be  a  settlement  amounting  to  several  pailfuls  in  the  septic 
tank  each  year,  and  provision  must  be  made  for  its  removal. 

Construction  of  the  Septic  Tank.  Concrete  is  the  best 
material  for  the  septic  tank.  The  tile  Hne  to  the  tank  from 
the  house  should  be  of  vitrified  bell-mouthed  tile  with 
cemented  joints. 


FARM  SANITATION 


505 


Fig.  308  is  a  general  view  of  a  septic  tank  which  has  been 
built  for  as  little  as  $18.65.  It  has  a  plank  top,  and  the  only 
means  of  cleaning  it  out  would  be  to  uncover  the  earth  and 
remove  the  planks.  Fig. 
309  is  a  more  expensive 
plant,  with  a  filter  bed 
attached.  The  filter  bed 
complete  will  cost  by  it- 
self about  $20.  The  best 
results  can  be  secured 
with  a  tank  provided  with 
a  siphon.  Fig.  310  shows 
a  plan  for  laying  the  tile 
system  to  filter  the  discharge  from  the  septic  tank. 

It  is  remarkable  how  thoroughly  sewage  can  be  purified  by 
an  efficient  plant.  Often  the  effluent  or  final  discharge  from 
the  filter  bed  will  compare  in  purity  with  the  best  well  water. 


Fig.  310. 
filtering      the 
tank. 


iscbarge 


tile    system   foi 
from     a      septic 


QUESTIONS 

1.  How  is  sewage  purified  that  is  discharged  into  a  river? 

2.  What  are  the  objections  to  a  cesspool  as  a  means  of  disposing 
of  sewage? 

3.  Discuss  the  construction  of  the  cesspool. 

4.  How  is  sewage  purified  in  a  septic  tank? 

5.  How  can  complete  purification  of  the  sewage  be  obtained? 

6.  Why  is  it  best  to  have  the  sewage  applied  intermittently  to  the 
filter  bed  or  irrigation  tile? 

7.  Discuss  the  construction  of  the  septic  tank. 

8.  Estimate  the  cost  of  a  sewage  disposal  plant  for  a  household  of 
ten  people. 


CHAPTER  LXXIX 
THE    NATURAL    LIGHTING    OF    FARM    BUILDINGS 

Development.  If  a  comparison  be  made  between  the 
farm  buildings  of  twenty-five  years  ago  and  those  which  are 
entitled  to  be  called  modern,  it  would  be  found  that  one  of  the 
principal  differences  lies  in  the  natural  lighting,  or  the  amount 
of  window  surface  provided.  This  change  is  due  largely  to  a 
more  general  recognition  of  the  value  of  light  as  a  sanitary 
agent. 

Purpose  of  Natural  Lighting.  The  natural  lighting  of 
farm  buildings  has  a  three-fold  purpose:  (1)  The  principal 
purpose,  to  make  the  buildings  more  sanitary  by  destroying 
disease  germs;  (2)  to  provide  a  more  convenient  and  pleasant 
place  for  the  attendants  to  care  for  the  animals;  and  (3)  to 
provide  more  pleasant  and  comfortable  quarters  for  the 
animals  to  feed  and  live  in.  As  stated,  the  principal  reason 
for  providing  adequate  natural  hght  for  farm  buildings  is  to 
seciu'e  sanitary  quarters  for  the  animals.  Direct  sunhght  is 
far  more  powerful  and  destructive  to  disease  germs  than 
diffused  or  reflected  hght,  and  for  this  reason  as  much  direct 
sunlight  as  possible  should  be  provided.  Usually  but  a  short 
time,  a  few  hours,  is  required  to  kill  germs  by  direct  sunhght. 

In  regard  to  the  value  of  diffuse  light  for  destroying 
germs.  Dr.  Weinzirl,  an  eminent  bacteriologist,  is  quoted  in 
King's  book  on  Ventilation  as  follows:  *'The  shortest  time 
in  which  diffuse  light  in  a  roorn  killed  the  bacillus  of  tuber- 
culosis was  less  than  a  day,  and  the  longest  time  was  less  than 
a  week;  generally,  three  or  four  days  of  exposure  killed  the  or- 
ganisms.   Some  pus-producing  bacteria  required  a  week's 

606 


FARM  SANITATION 


507 


time  to  kill  them,  while  some  intestinal  bacteria  were  killed 
in  a  few  hours.  It  was  also  found  that  bacteria  are  killed 
more  quickly  in  moist  air  than  in  dry,  contrary  to  general 
belief.  The  diffuse  hght  as  found  in  our  dwellings  is,  there- 
fore, a  hygienic  factor  of  great  importance,  and  where  direct 
sunhght  is  not  available  it  should  be  carefully  provided  for." 
It  is  beheved  that  the  above  quotation  represents  a  clear, 
authoritative  statement  of  the  value  of  diffuse  sunlight  in 
producing  sanitary  quarters. 

Location  of  Windows.  In  locating  the  windows,  great 
care  should  be  taken  that  sun- 
hght will  be  admitted  in  such 
a  way  as  to  allow  the  direct 
beams  of  light  to  sweep  the 
entire  floor.  The  angle  of 
incidence  of  the  sun's  rays,  or 
the  distance  of  the  sun  above 
the  horizon,  for  latitude  42° 
north  varies  from  70°  the  22nd 
of  June  to  26°  the  21st  of  Dec- 
ember. For  other  latitudes 
the  angle  of  incidence  is 
different.  At  the  spring  and 
fall  equinoxes,  which  take 
place  March  21  and  Sept- 
ember 21,  and  for  42°  N.  the 
angle  is  48°.  Sunhght  is  more 
useful  in  the  winter  time  than 
in  the  summer,  and  care 
should  be  taken  to  make  use  of  the  winter  sun  rather  than  the 
summer  sun.  For  practical  purposes  it  can  be  assumed  that 
the  most  desirable  sunhght  enters  the  windows  at  an  angle 
of  45°. 


Fig.  311.  A  sketch  showing  how 
the  angle  of  incidence  of  the  sun's 
rays  varies  throughout  the  year.  This 
is  at  latitude  42°  N. 


508 


AGRICULTURAL  ENGINEERING 


/^-v. 


Design  of  Windows.  The  window  casings  should  be 
designed  to  intercept  as  httle  of  the  direct  sunhght  as  possible. 
Stone  or  concrete  walls  of  considerable  thickness  should  be 

beveled  on  the  inside  so 
as  to  let  in  the  full  width 
of  the  beam  of  sunshine 
passing  through  the 
glass.  For  this  reason 
windows  that  are  long 
vertically  are  more  de- 
sirable and  more  effi- 
cient than  those  which 
are  wide  but  low.  In 
the  latter  instance  the 
casings  and  wall  cut  off 
a  large  proportion  of  the 
direct  light  admitted. 
Again,  wide,  over-hang- 
ing eaves  cut  off  much 
direct  sunshine  from  the  windows  located  directly  below. 

Size  of  Windows.  No  definite  rules  can  be  given  for  the 
amount  of  window  surface  to  provide  in  bams  and  other  farm 
buildings,  owing  to  the  fact  that  the  efficiency  of  the  windows 
depends  so  much  on  their  location.  It  is  good  practice,  how- 
ever, to  provide  one  square  foot  of  glass  for  every  20  to  25 
square  feet  of  floor  surface.  Judgment  must  be  used  in  this 
connection,  varying  the  amount  with  the  location  and  shape 
of  the  windows.  Dairy  barns  are  generally  provided  with  a 
larger  window  area  than  horse  barns. 

There  is  a  tendency  to  go  to  the  extreme  in  lighting  dairy 
bams.  Many  barns  have  been  built  during  recent  years  with 
entirely  too  much  window  surface.  Such  buildings  are  too 
cold  when  located  in  the  northern  climates,  at  least.    Ade- 


Fig.  312.  A  sketch  showing  the  effect 
of  thick  walls  upon  the  amount  of  direct 
sunlight  admitted,  the  greater  efficiency 
of  deep  windows  over  shallow  windows, 
and  also  the  effect  of  over-hanging  eaves. 


FARM  SANITATION  609 

quate  window  surface  does  not  add  materially  to  the  cost  of 
the  construction  and  should  not  be  admitted  for  this  reason. 
Wide  buildings  and  basement  barns  cannot  be  Hghted  well, 
and  for  this  reason  should  be  guarded  against.  It  is  to  be 
remembered  in  this  connection  that  natural  lighting  is  only- 
one  factor  in  providing  sanitary  quarters.  Cleanliness  and 
ventilation  are  more  important;  but  none  of  these  features 
should  be  neglected. 

QUESTIONS 

1.  Describe  the  changes  which  have  taken  place  in  the  natural 
lighting  of  farm  buildings. 

2.  What  is  the  threefold  purpose  of  the  natural  lighting  of  farm 
buildings? 

3.  What  value  has  direct  sunlight  in  destroying  disease  germs? 

4.  Discuss  how  windows  should  be  located  to  be  the  most  effective. 
6.  What  should  be  the  general  shape  of  windows,  and  what  may 

be  said  concerning  the  thickness  of  casings  and  width  of  eaves? 

6.  Discuss  the  relation  between  window  surface  and  floor  surfaee 
in  different  types  of  buildings. 


CHAPTER  LXXX 
LIGHTING  THE  COUNTRY  HOME 

Development.  It  is  extremely  interesting  to  study  the 
development  of  the  art  of  lighting,  or  illumination;  yet  it  is 
not  the  function  of  this  chapter  to  discuss  this  phase  of  the 
subject.  Our  fathers  and  mothers  were  compelled  while 
young  to  depend  on  the  tallow  candle,  the  tallow  dip,  or 
the  light  of  the  fire  in  the  fireplace.  History  relates  how 
many  of  our  famous  men  of  the  past  century  spent  hours 
in  the  flickering  fight  from  the  ''back  log"  poring  over  a  book 
which  they  were  endeavoring  to  master.  The  petroleum 
industry  was  not  developed  until  1860,  and  the  general 
use  of  kerosene  in  lamps  did  not  come  until  many  years 
after  this.  The  kerosene  lamp,  when  provided  with  a 
chimney  to  control  the  draft  and  produce  more  perfect  com- 
bustion, was  a  great  improvement  over  the  ill-smelfing 
and  smoking  tallow  candle  or  dip. 

The  various  sources  of  light  for  rural  conditions  are  the 
kerosene  lamp,  the  gasoline  lamp  or  system,  the  acetylene  lamp 
or  system,  and  the  electric  fighting  plant.  Alcohol  might  be 
burned  in  lamps,  but  at  its  present  cost  cannot  compete  with  the 
petroleum  oils.  These  various  systems  will  be  discussed  in  turn. 

The  Unit  of  Light — ^The  Standard  Candle.  In  comparing 
lamps  it  is  necessary  to  refer  to  the  unit  of  illumination,  the 
standard  candle  by  which  all  lamps  are  rated.  The  standard 
candle  for  the  United  States  and  Great  Britain  is  the  sperm 
candle  seven-eighths  of  an  inch  in  diameter  and  burning  120 
grains  of  sperm  per  hour.  This  standard  is  not  very  satisfac- 
tory, as  it  tends  to  vary.    The  International  Unit  of  Light 

510 


FARM  SANITATION  611 

was  adopted  by  the  United  States  July  1, 1909,  and  is  now  the 
legal  unit  of  light,  and  is  practically  equal  to  the  standard 
candle. 

The  art  of  measuring  the  illumination  of  any  source  of 
light  is  called  photometry.  The  principle  involved  consists 
in  placing  the  source  of  Ught,  or  the  lamp  to  be  measured  and 
a  standard  lamp  whose  candle  power  is  known,  at  such  dis- 
tances from  a  screen  that  the" intensity  of  the  light  from  each 
is  equal.  As  the  hght  from  ci  lamp  passes  out  in  all  directions, 
it  is  to  be  expected  that  the  intensity  of  the  hghtatall  points 
on  the  surface  of  a  sphere  at  a  certain  radius  from  the  source 
will  be  equal.  As  the  surfaces  of  spheres  vary  as  the  square 
of  their  radii,  the  intensity  of  Hght  varies  inversely  as  the 
square  of  the  distance  from  the  source.  This  assumes  that 
the  source  of  hght  is  a  sphere,  which  is  not  true. 

Kerosene  Lamps.  Kerosene  lamps  are  still  in  common 
use,  and,  although  they  have  some  very  serious  objections, 
their  merits  should  not  be  entirely  overlooked.  In  the  first 
place  kerosene  lamps  are  cheap  as  far  as  first  cost  is  con- 
cerned. The  fuel  is  cheap  and  can  be  obtained  almost  any- 
where. Kerosene  lamps  are  quite  safe;  in  fact,  they  excel 
many  others  in  this  respect.  There  is  more  danger  in  the 
matches  than  in  the  lamps  themselves.  The  lamps  are 
readily  portable,  which  is  not  true  of  all  sources  of  artificial 
hght. 

On  the  other  hand  there  are  many  disadvantages.  The 
odor  of  kerosene  lamps  is  not  pleasant,  although  far  more 
offensive  to  some  persons  than  to  others.  Kerosene  lamps 
require  attention  in  the  way  of  trimming  the  wicks  and  clean- 
ing the  chimneys.  If  a  large  number  of  lamps  are  to  be 
cared  for,  the  time  required  daily  is  considerable.  Much 
heat-  is  developed  by  a  kerosene  light,  which  at  times  may 
bo  a  serious  disadvantage.    The  lamp  also  consumes  a  large 


612 


AGRICULTURAL  ENGINEERING 


amount  of  oxygen  and  necessitates  more  rapid  ventilation. 

A  large  lamp  will  consume  more  oxygen  than  several  persons. 

There  is  more  or  less  smoke  com- 
ing from  the  flame,  which  settles 
as  soot  upon  the  furniture  and 
walls  of  the  room. 

The  light  from  a  kerosene  lamp 
is  a  yellowish  orange.  It  is  not 
white  enough  to  be  a  perfect  light. 
Authorities  differ  in  regard  to  the 
effect  of  the  light  from  a  kerosene 
lamp  upon  the  eye,  but  it  is  gen- 
erally regarded  as  a  quite  suit- 
able light.  The  addition  of  a 
mantle,  which  is  a  net  of  rare 
earths,  to  a  kerosene  lamp  to  in- 
close the  flame,  increases  the 
efficiency  many  fold.  This  will 
be  shown  definitely  in  the  data 
from  tests  which  will  follow. 
Mantles,  however,  are  very  fra- 
gile and  increase  the  cost  of  keep- 
ing the  lamp  in  service.  The 
average  kerosene  lamp  furnishes 
light  at  the  rate  of  15  to  30  candle 
power. 

It  is  to  be  noted  from  the 
table  that  the  mantle  has  a  de- 
cided effect  upon  the  efficiency 
of  lamps,  raising  the  candle- 
power-hours  per  gallon  from  600 


osfnf  limp.  ^  The^  efficiency^'of  to  over  3000.     GasoUue  lamps  are 

this   lamp   would   be   doubled   by  ;, 
the  use  of  a  mantle. 


in  reality  gas   lamps,  for   they 


FARM  8ANITATI02i 


513 


must  convert  the  liquid  into  gas  before  it  is  burned.  Gaso- 
line lamps  are  either  portable,  with  an  individual  generator, 
or  are  connected  to  a  system,  with  a  common  generator  for  the 
entire  system.  Again,  certain  gasoUne  plants  require  a 
special  grade  of  light  gasoUne  which  is  vaporized  upon  mixing 
with  air. 

Gasoline  Lamps.     Gasoline  lamps  are  not  as  safe  as  kero- 
sene lamps,  yet  when  properly  handled  should  not  be  danger- 

The  efficiency  of  lamps. 


Cost  per 

Candle 

Candle- 

candle- 

Kind  of  lamp 

Size 

Where  tested 

power 

po  wer-hrs. 

power-hr. 
Kerosene 

per    gal. 

at  lie. 

B.&H.  Burner. 

13^  in.  dia. 

la.  Exp.  Sta. 

33.5 

877 

.0125c 

Common  flat  wick 

1}4  in. wide 

Pa.  Exp.  Sta. 

11.66 

591  to 

.017c 

12.91 

789 

.017c 

Rochester. 

13^  in.  dia. 

Pa.  Exp.  Sta. 

16.02 
19.04 

350  to 
538 

.023c 

Saronia  with  Ar- 

gand  burner  and 

mantle 

Ji  in.  dia. 

Pa.  Exp.  Sta. 

27.46 
30.26 

1312  to 
1515 

.008c 

Chancester    with 

Argand  burner 

mantle 

Pa.  Exp.  Sta. 

30.6 
32.4 

3134  to 
3402 

.0034c 

ous.  They  should  be  filled  only  by  daylight,  and  care  should 
be  taken  not  to  let  the  gasoUne  become  exposed  to  the  air 
either  through  a  leak  or  by  spiUing.  A  gasoUne  lamp,  imless 
of  the  vaporizing  type,  requires  some  time  for  starting,  and 
must  be  heated  before  the  gasoline  can  be  generated.  While 
it  is  burning,  there  is  usually  a  hissing  noise  which  is  very 
disagreeable.  GasoUne  lamps  are  universally  mantle  lamps, 
and  for  this  reason  are  very  efficient.  The  most  efficient 
lamps  are  those  which  furnish  the  Uquid  to  the  lamps  under 
pressure.  The  gasoline  lamp  consumes  the  oxygen  of  the 
air  and  heats  it  much  as  the  kerosene  lamp. 

17— 


514 


AGRICULTURAL  ENGINEERING 
Effixyiency  of  gasoline  lamps. 


Kind  of  lamp 


Where  tested 


Candle 
power 


Candle- 

power-hra. 

per  gal. 


Cost  per  can- 
dle-power- 
hour  at  20c. 


Bracket  lamp 
Hanging  lamp 
Pressure  lamp  at  34  lbs. 

Underneath  generator 


la.  Exp.  Sta. 
la.  Exp.  Sta. 
la.  Exp.  Sta. 

Pa.  Exp.  Sta, 


51.2 

65.5 

300.0 

36  to  4G 


2948 
3180 
4550 

1885 


.0068c 
.0063c 
.0043? 

.0120c 


Fig.   314.     A  gasoline  lamp.     The  tubing 
coiled  so  as  to  appear  In  the  pic- 
ture. 


QUESTIONS 

1.  What  are  the  improved 
systems  of  lighting? 

2.  How  were  houses  light- 
ed by  artificial  means  in  early 
times? 

3.  What  is  the  common 
unit  of  light,  and  explain  how 
it  is  established? 

4.  Explain  how  the  illumi- 
nation of  any  source  may  be 
measured. 

5.  What  are  the  advan- 
tages and  disadvantages  of 
kerosene  lamps? 

6.  What  effect  does  the 
use  of  a  mantle  have  upon 
the  efficiency  of  lamps? 

7.  Discuss  the  merits  of 
gasoline  lamps. 

8.  How  does  the  cost  of 
light  from  kerosene,  alcohol, 
and  gasoline  lamps  compare? 

9.  Estimate  the  cost  of 
lighting  the  average  farm- 
house during  a  period  of  one 
year  with  the  different 
systems. 


CHAPTER  LXXXI 
THE  ACETYLENE  LIGHTING  PLANT 

The  Principle  of  the  Acetylene  Plant.  When  a  lighting 
system  for  the  farm  is  desired  which  will  furnish  the  equal  of 
city  service,  the  acetylene  plant  is  one  of  the  first  to  receive 
consideration.  Acetylene  gas  is  made  by  bringing  calcium 
carbide  in  contact  with  water.  In  portable  lamps  the  water 
is  allowed  to  drip  upon  the  carbide;  but  with  larger  plants,  the 
carbide  is  fed  into  a  rather  large  tank  of  water  mainly  to  keep 
the  temperature  of  the  gas  as  low  as  possible.  The  heating 
of  carbide  and  water  is  hke  that  of  unslaked  lime  and  water, 
and  the  resulting  residue  is  the  same — nothing  more  or  less 
than  common  whitewash. 

Calcium  Carbide.  The  calcium  carbide  is  made  by  sub- 
jecting a  mixture  of  coke  and  hme  to  the  intense  heat  of  the 
electric  furnace.  The  resulting  product  is  of  dark-gray  color 
with  a  sHghtly  crystalline  structure.  The  carbide  industry 
is  practically  monopolized  in  this  country  by  the  Union  Car- 
bide Sales  Company,  from  which  all  purchases  must  be  made. 
Distributing  depots  are  located  at  various  points  throughout 
the  United  States,  there  being  one  in  each  state,  or  perhaps 
more  in  some  instances.  The  cost  of  carbide  at  these  depots 
at  the  present  time  is  $3.75  per  hundred  pounds.  It  is  shipped 
in  metal  cans  as  third-class  freight.  The  carbide  is  no  more 
dangerous  than  unslaked  lime;  the  only  precaution  necessary 
is  to  keep  it  free  from  moisture.  There  are  four  sizes  of  car- 
bide carried  regularly  in  stock;  viz.,  Lump,  Egg,  Nut,  and 
Quarter.  The  last  two  sizes,  Nut  3^  inch  by  %  inch,  and 
Quarter,  34  inch  by  1/12  inch,  are  the  two  commonly  used  in 
carbide  feed  generators. 

515 


516  AGRICULTURAL  ENGINEERING 

Acetylene  Gas.  Acetylene  is  a  colorless,  tasteless  gas 
composed  entirely  of  carbon  and  hydrogen.  It  is  lighter  than 
air,  but  much  heavier  than  coal  gas.  Acetylene  burns  with 
a  very  white  Hght,  almost  Hke  sunlight.    It  is  easy  on  the  eyes 


m 

:■   •             1 

I 

'^^^ 

Fi&.    315.     A    35-li&ht  acetylene   generator. 

and  enables  one  to  distinguish  colors  accurately.  The  com- 
bustion of  acetylene  deprives  the  air  of  about  ly^  cubic  feet 
of  oxygen  for  each  cubic  foot  burned.  The  flame,  for  equal 
candle  power,  produces  less  heat  than  the  kerosene  lamp. 


FARM  SANITATION 


517 


Being  a  rich  gas,  acetylene  will  form  a  dangerously  explo- 
sive mixture  with  air;  yet  an  explosive  mixture,  which  must 
contain  between  J^  to  25  times  as  much  air  as  gas,  is  so 
unUkely  to  occur,  on  account  of  the  ease  by  which  gas  leaks 
are  detected,  that  accidents  are  seldom  heard  of. 

Acetylene  gas  will  cause  asphyxiation,  yet  not  nearly  so 
readily  as  coal  gas,  which  is  used  for  illumination  in  the  cities. 
No  fatal  results  from  inhalation  are  on  record,  and  it  is 
claimed  that  death  could  not  occur  until  the  gas  was  present 
in  the  proportion  of  at  least  20  per  cent. 

Production  of  Acetylene  Gas.  When  calcium  carbide  is 
mixed  with  water,  each  pound  should,  if  the  carbide  is  chem- 
ically pure,  yield  53^  cubic  feet  of  gas.  This  gas  is  very  rich, 
containing  about  1700  British  thermal  units  per  cubic  foot, 
nearly  three  times  that  of 
coal  gas.  The  commer- 
cial carbide  yields  from 
43^  to  5}4:  cubic  feet,  de- 
pending somewhat  upon 
its  purity,  the  moisture 
absorbed,and  the  amount 
of  dust  present-  Theo- 
retically, .562  pound  of 
water  will  be  needed  for 
each  pound  of  carbide, 
but  in  practice  as  much 

.    ,  ,  Fig.  316.     A     section     of     the     generator 

as  eight  pounds  are   sup-  shown    in    Fig.    315.        ^    is    the    motor   or 

1*    J        rrt'L.  J.  clockwork   for   operating  the   carbide   feed, 

plied.        i  ne     most     com-  B  is  the  carbide  feed.  C  Is  the  weight  for 

,  ,  J  running    the   motor,   D   is   the   carbide   bin, 

mon  size  01    burner  used  E    is    the    agitator    in    the   water    tank    for 

1  /       -L"     i?      J.     £  Storing    up     the    residue    before    cleaning, 

consumes  34  cubic  toot  01  F   is    the    gas    holder,    G   is    the    gas   filter, 

,  J       .  and  H  is  the  pipe  line  to  supply  lamps. 

gas  per  hour,  and  gives  a 

25-candle-power  Hght.     Other  standard  sizes  are  the  1,  ^, 

and  M  cubic  foot  burners.    These  burners  are  all  forked  in 


518  AGRICULTURAL  ENGINEERING 

such  a  way  that  two  jets  of  flame  are  directed  toward  each 
other,  forming  a  fan-shaped  flame. 

Mantles  are  not  used  with  acetylene  burners,  owing  to 
the  fact  that  it  is  almost  impossible  tohght  the  gas  without  a 
slight  explosion  or  jar  which  would  destroy  the  mantle.  If 
mantles  could  be  used  they  would  raise  the  efficiency  of  the 
lamps  many  fold. 

Cost  of  Light.  If  it  is  assumed  that  one  pound  of  carbi  de, 
costing  $4  per  hundredweight,  will  furnish  five  cubic  feet  of 
gas,  and  that  a  burner  using  one-half  cubic  foot  per  hour  will 
furnish  a  25-candle-power  light,  it  is  easy  to  calculate  the  cost 
of  acetylene  light  per  candle-power-hour  for  comparison  with 
other  lighting  systems.  Thus  if  J^  cubic  foot  of  gas  costs  4/10 
cent,  which  is  the  cost  of  25  candle-power-hours  of  light,  one 
candle-power-hour  will  cost  1/25  of  4/10  cent  or  .016  cent. 

In  a  test  of  a  portable  lamp,  made  at  the  Pennsylvania 
agricultural  experiment  station,  from  127  to  140  candle- 
power-hours  were  obtained  from  a  pound  of  carbide,  costing 
5  9/10  cents  per  pound.  This  would  make  the  cost  of  light 
per  candle-power-hour  .043  cent. 

Essentials  of  a  Good  Acetylene  Generator.  All  acetylene 
Hght  plants  must  have  a  generator  whose  function  is  to  feed 
the  carbide  to  the  water,  or  the  water  to  the  carbide,  which 
is  less  usual,  as  the  gas  is  used.  The  essentials  of  a  good 
acetylene  generator  may  be  summarized  as  follows : 

1.  There  should  be  no  possibifity  of  the  existence  of  an 
explosive  mixture  in  the  generator  at  any  time. '  The  National 
Board  of  Fire  Underwriters  has  prepared  a  fist  of  generators 
which  have  passed  inspection ;  and  each  buyer  should  see  that 
the  make  of  machine  purchased  has  been  inspected  and  listed. 

2.  The  generator  must  insure  cool  generation. 

3.  The  construction  must  be  tight  and  heavy  enough  to 
resist  rapid  deterioration. 


FARM  SANITATION  519 

4.  It  should  be  simple  in  construction  so  as  to  be  readily 
understood  and  not  likely  to  get  out  of  order. 

5.  It  should  be  capable  of  being  recleaned  and  recharged 
without  loss  of  gas  into  the  room. 

6.  There  should  be  a  suitable  indicator  to  show  how 
much  carbide  remains  unused. 

7.  The  carbide  should  be  completely  used  up,  generating 
the  maximum  amount  of  gas. 

Size  and  Cost  of  Plant.  Generators  are  made  in  various 
sizes,  the  rating  being  based  upon  the  number  of  3^-foot 
Ughts  that  can  be  supplied  with  gas.  The  sizes  vary  from 
20-light  to  1000-Ught,  but  25,  30,  and  35  are  the  usual  sizes. 
The  list  prices  of  these  are  120,  135,  and  150  dollars,  respec- 
tively. In  addition  to  the  cost  of  the  generator,  the  cost  of 
the  piping,  fixtures,  and  installation  must  be  added.  For  an 
eight-room  house,  the  total  cost  will  be  about  as  follows: 

Generator $150 

Piping  system 40 

Drain  and  foundation  for  generator 10 

Fixtures,  eight  rooms  and  basement 40 

Bam  additional 15 

Total $255 

It  is  to  be  understood  that  this  estimate  cannot  be  made 
very  definite  owing  to  the  varying  number  of  fixtures  required 
and  the  cost  of  labor,  freight,  etc. 

QUESTIONS 

1.  How  is  acetylene  gas  made?    How  is  carbide  made?, 

2.  Discuss  the  cost  and  sizes  of  carbide. 

3.  Describe  the  characteristics  of  acetylene  gas. 

4.  Discuss  the  cost  of  Hght  from  acetylene  gas. 

5.  What  are  the  essentials  of  a  good  generator? 

6.  Itemize  the  cost  of  an  acetylene  plant. 

7.  What  care  should  be  used  in  installing  an  acetylene  system? 


CHAPTER  LXXXII 
THE  ELECTRIC  LIGHTING  PLANT 

Development.  Two  great  improvements  have  recently 
been  brought  about  which  have  done  much  to  make  the 
private  electric  plant  far  more  successful  than  ever  before. 
In  the  first  place,  the  new  tungsten  incandescent  lamp  has 
practically  reduced  the  consumption  of  electricity  per  candle- 
power-hour  to  about  one-third  the  former  rate.  In  the  second 
place,  there  have  been  some  very  decided  improvements 
in  storage  battery  construction,  not  only  making  them  more 
reUable,  but  cheaper. 

Electric  Light.  Illuminating  engineers  agree  that  the 
incandescent  electric  light  is  the  nearest  approach  to  the  ideal 
hght  that  is  now  to  be  obtained.  Its  first  great  merit  Hes  in 
its  convenience.  It  is  only  necessary  to  turn  a  button  or 
switch  and  the  light  is  on  or  off  as  desired.  It  is  the  cleanest 
of  all  fights,  no  dust,  no  soot,  and  no  odor.  Furthermore,  the 
electric  light  does  not  vitiate  the  air  by  consuming  the  oxygen. 
Of  all  lights  it  is  by  far  the  safest  and  may  be  taken  directly 
into  places  filled  with  combustibles. 

The  serious  objection  to  the  electric  fight  which  has  been 
raised  in  the  past  is  its  cost.  The  new  tungsten  lamp  has 
done  much  to  remove  this  objection,  where  it  can  be  used, 
although  it  is  rather  fragile  and  cannot  be  used  where  the 
lamp  is  subject  to  shocks  or  sharp  vibrations.  Further,  the 
cost  of  electric  fight  may  be  somewhat  overlooked  on  account 
of  the  advantages  enumerated.  The  first  cost  of  installing  an 
electric  plant  is  large,  but  not  so  much  greater  than  the  cost 
of  installing  an  acetylene  or  gasoline  plant.     In  addition  to 

520 


FARM  SANITATION 


521 


lighting,  the  electric  current  may  be  used  for  other  purposes- 
small  motors,  electric  irons,  etc. 

The  Electric  Plant.  It  does  not  seem  practical  to  install 
an  electric  plant  large  enough  to  furnish  power  to  the  various 
machines  used  on  the  farm.  Not  only  would  the  cost  of  in- 
stallation be  very  great,  but  such  a  plant  when  used  for  light- 
ing would  be  very  inefficient.  An  electric  fighting  plant 
consists  primarily  of  a  source  of  power  or  a  motor  of  some  sort, 
a  generator  or  dynamo  to  furnish 
the  current,  the  wiring,  the  lights, 
and,  under  all  normal  conditions, 
a  storage  battery  to  supply  cur- 
rent when  the  motor  and  gen- 
erator are  not  running. 

The  Source  of  Power.  Water- 
power  makes  an  ideal  power  for 
the  plant,  as  it  is  almost  always 
very  cheap.  It  is,  however,  not 
often  available;  hence  the  princi- 
pal source  of  power  for  the  farm 
electric  plant  is  the  gasofine  or  kerosene  engine.  These,  as 
has  been  shown,  have  developed  to  the  point  where  they  are 
quite  refiable,  and  the  power  is  furnished  in  small  units  at 
a  very  reasonable  cost.  Furthermore,  the  gasoline  engine 
requires  the  minimum  of  attention  while  running,  which 
is  an  essential  feature  of  the  entire  private  electric  plant. 
Definitions.  In  discussing  an  electric  plant,  recourse 
must  be  made  to  some  electrical  terms.  Electric  current  has 
two  properties:  (1)  The  pressiu-e  or  the  voltage,  which  is  the 
measure  of  the  tendency  on  the  part  of  an  electric  current  to 
flow;  and  (2)  the  amount  of  current  flowing,  or  the  amperage. 
Thus  a  110-volt  lamp  requires  110  volts  of  pressure  or  voltage 
to  make  its  filament  glow  brightly.  If  the  lamp  be  a  16- 
candle-power  carbon  filament  lamp  only  one-half  ampere  will 


carbon  filament  electric  lamp;  B 
is  the  new  tungsten  lamp,  which 
is  much  more  efficient. 


022  AGRICULTURAL  ENGINEERING 

pass  through  the  lamp.  The  product  of  the  volts  by  the 
amperes  gives  the  electric  power  in  watts,  the  watt  being  the 
unit  of  power.  Thus  for  the  lamp  just  referred  to,  the  current 
consumption  would  be  1 10  x3^,  or  55  watts.  One  horsepower 
is  equal  to  746  watts.  The  output  of  dynamos  or  generators 
is  rated  in  kilowatts,  or  units  of  1000  watts.  Electricity  is 
purchased  by  the  kilowatt-hour,  which  is  electric  current  at 
the  rate  of  one  kilowatt  continued  for  one  hour.  One  kilo- 
watt equals  1.34  horsepower;  thus  to  drive  a  one-kilowatt 
dynamo,  a  IJ/^-  or  2-horsepower  engine  is  provided,  as  some 
power  is  lost  in  the  friction  of  the  dynamo  itself. 

Selection  of  the  Plant.  In  deciding  upon  a  plant  one  of 
the  first  questions  that  arises  is  the  matter  of  the  voltage  at 
which  the  plant  is  to  be  operated.  Electric  light  plants  are 
now  made  to  furnish  current  at  30,  60,  110,  or  even  higher 
voltage.  The  common  voltages  are  30  and  110.  The 
lower  voltages  have  some  advantages;  viz.,  (1)  first  cost  of 
the  storage  battery  is  lower;  (2)  the  battery  has  fewer  parts; 
(3)  it  can  be  used  better  with  low  candle-power  lamps; 
and  (4)  the  lamps,  having  shorter  filaments,  are  stronger. 

The  disadvantage  of  a  low  voltage  lies  primarily  in  the 
fact  that  it  is  not  standard  with  any  lighting  plants  and  is 
inconvenient  to  procure  lamps  and  other  fixtures  for  it. 
There  is  a  decided  saving  with  high  voltage,  however,  in 
connection  with  the  wiring,  especially  if  the  current  is  to  be 
transmitted  far,  since  the  size  of  wire  required  to  furnish  a 
given  Hght  with  electricity  varies  inversely  with  the  voltage. 
In  other  words,  a  wire  will  transmit  twice  as  much  electricity 
through  a  given  size  at  110  volts  as  at  55  volts. 

If  the  maximum  number  of  25-watt  lamps  in  service  at 
one  time  does  not  exceed  20,  or  the  demands  upon  the  dynamo 
from  miscellaneous  sources  such  as  motors,  flat  iron,  etc., 
does  not  exceed  500  watts,  a  one-half  kilowatt  generator 
may  be  used.    A  one-horsepower  gasoline  engine  will  furnish 


FARM  SANITATION 


623 


the  power  unless  required  to  do  other  work  while  running  the 
generator.  If  pumping,  churning,  and  other  forms  of  light 
work  are  contemplated,  a  two-horsepower  engine  will  usually 
be  found  very  satisfactory.  The  storage  battery  must  con- 
tain 56  cells,  and  if  they  are  of  the  20-ampere-hour  size  they 
will  furnish  all  of  the  lamps  with  current  for  four  hours. 


Fig.  318.      Engine,  dynamo,  storage  battery,  and  switchboard  of  an  elec- 
tric  lighting  plant. 

The  Cost  of  the  Plant.    The  total  cost  of  plant  may  be 
estimated  as  follows: 

1  2-horsepower  gasoline  engine $125 

1  3^-kilowatt  generator 60 

1  storage  battery^  20-ampere-hour,  56  cells  at  $2.50 140 

1  complete  switchboard 75 

17  tungsten  lamps 7 

12  carbon  lamps 3 

Wiring 50 

Fixtures 30 

Total  cost $490 

The  Cost  of  Light.    The  cost  of  operating  the  plant  will 
be  principally  that  of  gasohne,  which,  at  the  usual  price,  will 


524  AGRICULTURAL  ENGINEERING 

be  between  13/^  and  2  cents  per  hour.  Twenty  25-watt  lamps 
will  furnish  400  candle-power.  Thus  the  cost  per  candle- 
power-hour  might  be  at  a  minimum  .00375  to  .005  cents.  As 
the  plant  will  seldom  be  operated  at  full  capacity,  the  aver- 
age cost  will  be  much  greater,  perhaps  double. 

Operation.  The  electric  plant  is  not  difficult  to  operate 
by  one  who  has  some  knowledge  of  electrical  machinery. 
The  engine  and  the  dynamo  will  not  require  a  great  amount  of 
attention.  The  storage  must  be  supplied  with  electrolyte 
from  time  to  time.  The  battery  is  also  the  least  durable  part 
of  the  entire  plant.  Perhaps  a  new  set  of  electrodes  for  the 
battery  will  be  needed  at  the  end  of  five  years.  A  good  engine 
ought  to  last  at  least  ten  years. 

QUESTIONS 

1.  What  improvements  have  made  the  electric  lighting  plants 
practical  for  farm  homes? 

2.  What  are  the  advantages  of  electric  light? 

3.  Discuss  the  most  serious  objections  to  electric  light. 

4.  Is  it  generally  practical  to  install  an  electric  lighting  plant  large 
enough  for  power  service? 

5.  Discuss  the  various  sources  of  power  for  electric  lighting  plants. 

6.  Define  voltage.     Amperage. 

7.  What  is  a  watt?    A  kilowatt? 

8.  What  is  the  relation  between  watts  and  candle  power  with  tung- 
sten lamps? 

9.  What  are  the  advantages  of  a  low- voltage  system? 

10.  What  are  its  disadvantages? 

11.  Itemize  the  cost  of  an  electric  lighting  plant. 

12.  Discuss  the  cost  of  electric  light. 

13.  Discuss  the  care  and  maintenance  of  an  electric  lighting  plant. 


CHAPTER  LXXXIII 
HEATING  THE  COUNTRY  HOME 

Systems  of  Heating.  There  are  four  systems  of  heating 
farm  houses  in  use : 

1.  By  stoves. 

2.  By  a  hot-air  furnace. 

3.  By  a  hot-water  furnace  and  radiators. 

4.  By  a  steam  furnace  and  radiators. 

Stoves.  The  first  of  these  is  in  common  use,  and  perhaps 
Httle  can  be  written  here  which  will  add  to  the  general  infor- 
mation upon  the  subject.  The  stove  was  invented  to  bum 
coal  shortly  after  coal  was  discovered,  for  the  fireplaces  of 
the  time  were  not  adapted  to  the  purpose.  As  usually 
designed  the  stove  is  not  an  efficient  device,  as  perhaps  50 
per  cent  of  the  heat  is  lost  up  the  chimney.  It  has  other 
more  serious  shortcomings,  however.  In  the  first  place  the 
stove  d  >es  not  produce  a  uniform  temperature,  owing  to  the 
fact  that  the  air  circulation  within  the  room  is  not  perfect. 
The  success  of  any  heating  system  depends  primarily  upon 
perfect  circulation  of  the  air.  Air  near  the  hot  stove  expands 
upon  heating,  becomes  fighter  and  rises  to  the  ceifing,  and 
colder  air  takes  its  place.  As  the  warmest  part  of  the  stove 
is  several  feet  from  the  floor,  the  upper  part  of  the  room  is 
usually  much  warmer  than  the  lower.  The  inconvenience  of 
handling  and  storing  the  fuel .  in  the  room,  and  the  dirt, 
smoke  and  gases  that  are  apt  to  result  are  also  objectionable. 

If  several  rooms  are  to  be  heated,  the  management  of  the 
stoves  becomes  a  troublesome  matter.  Almost  any  kind  of 
fuel  may  be  used  in  a  stove,  which  is  an  advantage  decidedly 

525 


526  AGRICULTURAL  ENGINEERING 

in  its  favor.  Although  coal  requires  less  labor,  wood  is  a 
clean  and  very  desirable  fuel.  In  certain  sections  of  the 
country  the  fuel  used  is  mainly  corn  cobs  and  other  trash,  and 
the  stoves  used  are  the  so-called  air-tight  stoves  which  have 
a  large  magazine  into  which  a  bushel  or  more  fuel  may  be 
placed  at  one  time.  This  magazine  obviates  the  necessity  of 
feeding  the  fuel  at  short  intervals.  There  is,  however,  some 
danger  from  the  explosion  of  the  gas  which  is  generated  from 
fresh  fuel  before  the  flames  start.  The  heat  of  the  smoulder- 
ing fire  upon  which  fresh  fuel  is  placed  drives  off  certain 
combustible  gases,  which  are  ignited  as  soon  as  a  flame 
starts  up. 

By  far  the  most  satisfactory  stove  for  the  cold  winters  of 
the  North  is  the  hard-coal  burner.  When  of  sufficient  size 
and  well  designed,  with  a  good  large  magazine,  the  hard-coal 
burner  may  be  used  to  heat  several  rooms  to  a  comfortable 
temperature.  The  high  cost  of  hard  or  anthracite  coal  in 
certain  sections  of  the  country  renders  the  use  of  such  a  heater 
quite  expensive. 

Radiators.  In  houses  equipped  with  stoves  an  upper 
room  can  be  comfortably  heated  by  extending  the  stove  pipe 
into  the  room  and  providing  a  radiator.  This  plan  is  highly 
commendable,  as  there  is  no  additional  expense  connected 
with  its  use  other  than  the  cost  of  the  radiator,  which  should 
not  exceed  $8,  the  value  of  a  good  one. 

Warm-Air  Furnaces.  Heating  houses  by  means  of  warm- 
air  furnaces  does  not  differ  materially  from  the  use  of  stoves. 
The  furnace  is  simply  a  large  stove  placed  in  the  basement, 
with  pipes  to  convey  the  heated  air  to  the  various  rooms 
above.  By  placing  the  furnace  in  the  basement  many  of  the 
objections  to  the  stove  are  overcome.  First,  the  dirt  con- 
nected with  the  firing  and  cleaning  is  kept  where  it  is  least 
objectionable.    Proper  circulation  of  the  air  may  be  secured 


FARM  SANITATION 


627 


by  arranging  the  pipes  so  that  the  temperature  may  be  kept 
uniform  in  all  parts  of  the  house. 

The  warm-air  furnace  has  an  advantage  in  that  a  house 
may  be  heated  up  quickly,  and  hkewise  the  disadvantage  that 
the  house  will  cool  quickly  when  the  fire  goes  down,  owing  to 
the  fact  that  there  is  no  storage  of  heat.  The  hot-air  furnace 
is  very  bad  about  conducting  dust  and  smoke  into  the  rooms. 
Often  cheesecloth  strainers  are  provided  in  the  fresh  air  out- 
lets to  keep  out  the  dust.  The  average  life  of  a  hot-air 
furnace  will  not  exceed  8  to  10 
years,  and  when  it  becomes  old  the 
plates  are  quite  Hkely  to  be  cracked 
or  warped  in  such  a  way  that 
there  is  a  serious  leakage  of  smoke 
and  gas  into  the  rooms.  It  is  to 
be  noted  'in  this  connection  that 
the  furnace  is  so  large  that  it  must 
be  built  in  sections,  and  seams 
cannot  be  avoided.  As  air  does 
not  have  the  property  of  absorbing 
a  large  amount  of  heat  quickly, 
the  plates  and  castings  are  easily 
overh^ted. 

In  strong  winds  the  circulation  of  the  air  in  the  flues  is 
seriously  interfered  with.  Often  there  is  a  corner  room  more 
exposed  than  the  others  that  cannot  be  heated  with  the  hot- 
air  system. 

Installation.  In  planning  a  house  in  which  the  warm-air 
system  is  to  be  used,  thought  should  be  taken  to  give  the  fur- 
nace a  central  location,  that  there  shall  be  no  long  horizontal 
air  pipes  through  which  it  will  be  difficult  to  start  a  draft. 
The  size  of  the  hot-air  furnace  is  usually  designated  by  the 
diameter  of  the  fire  pot,  which  ranges  from  20  to  30  inches 


Fig.    319. 


A   typical 
furnace. 


warm-air 


628 


AGRICULTURAL  ENGINEERING 


and  over.  The  hot-air  system  of  heating  is  much  less  expen- 
sive, as  far  as  cost  of  installation  is  concerned,  than  the  hot- 
water  or  steam  system. 
The  cost  of  a  first-class 
furnace  with  double  pip- 
ing to  protect  the  wood- 
work from  becoming 
over-heated,  in  a  house 
of  six  rooms,  ought  not 
to  exceed  $200. 

The  Hot-Water  Sys- 
tem. The  hot-water  fur- 
nace with  suitable  radi- 
ators represents  the  most 
perfect  system  of  house 
heating,  but  it  is  the 
most  expensive  of  all  and 
is  shghtly  more  difficult 
to  regulate.  Water  is 
heated  by  the  furnace, 
and  the  consequent  ex- 
pansion and  reduction  in 
weight  cause  it  to  flow 
to  the  radiators  above, 
where  it  becomes  cooled 
and  consequently  heav- 
ier, causing  it  to  flow 
downward  to  be  heated 

Fig.    320.     A   hot-water   heating   system,  again.  An       CXpaUsioU 

The   locomotive   type    of   furnace   or  boiler,  ,        ,      .  •  j    j        t_ 

although  not  in  general  use,   is  said  to  be  taUK    IS  prOVlaeCl    aOOVe 

quite  satisfactory.  n    xr  j*    j.            x 

all  the  radiators  to  ac- 
commodate the  extra  volume  of  the  heated  water.  The 
success  of  the  hot-water  system  consists  in  providing  a  fur- 


FARM  SANITATION  529 

nace,  piping,  and  radiators  of  sufficient  size.  The  capacity  of 
a  furnace  depends  primarily  upon  its  heating  surface,  al- 
though the  size  is  commonly  designated  by  the  size  of  the 
fire  pot. 

Radiators.  Radiators,  designed  to  give  off  heat  from  the 
water  heated  in  the  furnace,  are  made  of  cast-iron,  pressed 
steel,  or  pipe.  In  any  case  the  amount  of  heat  furnished  is 
determined  by  the  amount  of  surface  from  which  the  heat 
may  radiate.  This  is  always  measured  in  square  feet,  and 
one  feature  of  the  design  of  a  hot-water  system  is  to  provide  a 
sufficient  amount  of  radiating  surface  to  heat  each  room. 
Radiators  may  be  obtained  with  greater  or  less  number  of 
sections  in  various  sizes,  to  furnish  any  amount  of  radiating 
surface  desired. 

Estimating  th-e  Radiation.  One  rule  for  determining  the 
amount  of  radiation  for  cUmates  where  the  temperature  occa- 
sionally falls  below  zero  is  as  follows : 

cubical  contents  of  room 

Square  feet  of  radiation   =  ■ + 

200 
square  feet  of  glass 

+  lineal  feet  of  exposed  wall. 

2 

The  hot-water  system  will  successfully  heat  rooms  on  the 
side  of  the  house  exposed  to  strong  wind.  It  is  much  cleaner 
and  the  plant  will  last  at  least  twice  as  long  as  the  hot-air 
system.  The  cost  will,  however,  be  from  one-half  to  double 
that  of  the  hot-air  system.  It  is  claimed  that  the  hot-water 
system  uses  one-third  less  fuel  than  the  hot-air  furnace. 

A  steam  system  may  be  installed  for  heating  residences, 
but  it  requires  close  attention  and  so  is  seldom  used.  In 
large  buildings  and  factories  it  is  universally  used,  the  use  of 
steam  reducing  to  some  extent  the  size  and  cost  of  piping. 


530  AGRICULTURAL  ENGINEERIN0 

QUESTIONS 

1.  What  are  the  four  systems  of  heating  farm  houses  now  in  use? 

2.  Discuss  the  advantages  and  disadvantages  of  stoves. 

3.  What  are  the  fuels  commonly  used  in  stoves,  and  what  are  the 
advantages  of  each? 

4.  What  is  considered  the  most  satisfactory  stove  for  cold  climates? 

5.  How  may  upper  rooms  be  heated  with  the  stoves  below? 

6.  What  are  the  advantages  of  a  warm-air  furnace  over  stoves? 

7.  How  durable  is  the  warm-air  furnace? 

8.  How  much  will  a  warm-air  furnace  installation  cost  for  a  six- 
room  house? 

9.  What  are  the  advantages  and  disadvantages  of  the  hot-water 
system? 

10.  Upon  what  does  the  capacity  of  a  hot-water  furnace  depend? 

11.  Of  what  materials  are  radiators  made? 

12.  Explain  by  a  practical  example  how  the  radiating  surface 
required  for  a  house  may  be  estimated. 

13.  How  will  the  cost  of  a  hot- water  system  compare  with  a-  warm- 
air  system? 

14.  What  are  some  of  the  objections  to  a  steam  heating  system  ioi 
farm  houses? 


CHAPTER  LXXXIV 
VENTILATION  OF  FARM  BUILDINGS 

Importance  of  Ventilation.  One  of  the  most  important 
features  involved  in  the  design  of  farm  buildings  is  that  of 
ventilation.  It  is  generally  recognized  that  men  and  animals 
must  have  fresh  air,  and  the  most  favorable  conditions  for 
life  and  health  are  attained  when  the  air  is  as  pure  as  the  open 
atmosphere.  It  is  not  practical  to  provide  air  as  pure  as  this 
to  animals  housed  in  buildings  designed  primarily  for  shelter 
and  warmth. 

The  Standard  of  Purity.  The  standard  of  purity,  or  the 
extent  to  which  pure  air  may  be  vitiated  with  expired  air  and 
still  be  fit  to  breathe,  is  a  much-argued  point.  For  conven- 
ience, the  purity  of  air  is  designated  by  the  number  of  parts 
of  carbon  dioxide  in  10,000  parts  of  air.  Pure  air  contains 
about  four  parts  of  carbon  dioxide  in  each  10,000  parts. 

De  Chaumont,  an  authority  on  ventilation,  holds  that  six 
parts  of  carbon  dioxide  in  10,000  parts  of  air  should  be  the 
standard,  and  other  authorities  recommend  various  and 
greater  amounts.  The  late  Professor  F.  H.  King,  of  Wiscon- 
sin, recommended  16  parts  as  the  correct  standard,  but  em- 
phasized the  great  need  of  experiments  to  determine  definitely 
the  correct  standard.  There  is  little  doubt  that  if  this  lower 
standard  were  maintained  generally,  ventilation  conditions 
would  be  much  better  than  they  are  now. 

Purpose  of  Ventilation.  The  purpose  of  ventilation  is 
threefold:  (1)  To  supply  pure  air  to  the  lungs  of  the  animals; 
(2)  to  dilute  and  remove  the  products  of  respiration;  and  (3) 
to  carry  away  the  odors  or  the  effluvium  arising  from  the 

531 


532 


AGRICULTURAL  ENGINEERING 


excreta.  The  first  of  these  is  the  all-important  purpose;  for 
no  animal  can  live  more  than  a  few  minutes  without  air,  but 
is  able  to  go  for  some  time  without  either  food  or  water.  The 
quantity  of  air  breathed  daily  by  an  animal  greatly  exceeds 
the  total  quantity  of  food  and  water.  This  is  indicated  by  the 
following  table: 


Amount  o 

f  air  breathed  by  different  animals. 

(Collins  Table.) 

Per  hour 

Per  24  Hours 

Cu.  ft. 

Pounds 

Cu.  ft. 

Horse 

141.7 

272 

3402 

Cow 

116.8 

224 

2804 

Pig 

46.0 

89 

1103 

Sheep 

30.2 

58 

726 

Man 

17.7 

34 

425 

Hen 

1.2 

2 

29 

To  maintain  the  standard  set  by  Professor  King,  which 

requires  that  the  air  at  no  time  shall  contain  more  than  3.3 

per  cent  of  air  once  breathed,  the  following  amounts  of  air  will 

be  required  each  hour   for  the  various  animals  indicated. 

This  standard  may  be  stated  as  96.7  per  cent,  representing 

the  purity  of  the  air,  and,  as  before  stated,  it  is  equivalent  to 

between  16  and  17  parts  of  carbon  dioxide  per  10,000  parts 

of  air. 

Amount  of  air  required  per  hour  to  maintain  a  standard  of  g6.y  per 
cent. 


4296  cu.  ft.  per  head 
3542    "     " 


Horses 

Cows 

Swine 1392 

Sheep 917 

Hens 35 

Man 637 

Ventilation  finally  resolves  itself  into  the  problem  of  find- 
ing a  process  of  dilution  or  mixing  the  air  in  the  building  with 


FARM  SANITATION 


533 


fresh  air  fast  enough  to  prevent  the  air  from  becoming  foul 
beyond  the  permissible  standard.  The  process  of  dilution 
may  be  accompUshedinatleast  four  different  ways,  as  follows: 

1.  By  a  process  of  diffusion  through  cloth  curtains. 

2.  By  the  action  of  winds. 

3.  By  the  difference  in  weight  of  masses  of  air  of  un- 
equal temperature. 

4.  By  mechanical  methods. 

Cloth  Curtain  Ventilators.  Poultry  houses  quite  gener- 
ally and  dairy  barns  in  several  instances  have  been  ventilated 
by  providing  thin  muslin  or  cheesecloth  curtains  in  place  of 
the  usual  window  glass.  The  theory  of  ventilation  in  this 
case  holds  that  there  is  a  diffusion  of  the  foul  air  outward  and 
the  pure  air  inward  through  these 
curtains.  Experiments  which  have 
been  conducted  to  date,  to  deter- 
mine definitely  the  efficiency  of  this 
system,  would  indicate  that  it  is 
unsatisfactory  and  unrehable.  It 
is  quite  impossible  with  any  rea- 
sonable amount  of  curtain  surface 
to  provide  the  necessary  pure  air. 

Action  of  Winds.  The  action 
of  the  winds  is  one  of  the  sim- 
plest methods  of  producing  venti- 
lation. For  instance,  the  wind  pro- 
vides ventilation  when  two  windows      Fig.     321.    A    window    ar- 

.  ranged    so    as    to    allow    air    to 

are  opened   on  opposite  sides  of  a    enter  with  the  least  draft.     It 

.  may  be  hinged   at    the   bottom 

bmldmg.     Such   an  arrangement  and  made  to  close  between  the 
would  not  be  satisfactory  on  ac- 
count of  the  direct  drafts  produced,  subjecting  the  animals 
to  chills.    The  dangers  from  drafts  are  overcome  to  a  large 
extent  by  providing  suitable  inlets  and  outlets. 


634 


AGRICULTURAL  ENGINEERINa 


The  Sheringham  valve  makes  a  satisfactory  inlet.  This 
is  arranged  by  hinging  the  window  at  the  bottom  and  allow- 
ing it  to  drop  inward  at  the  top  between  cheeks  or  triangular- 
shaped  side  pieces.  The  air  in  striking  the  inclined  window 
is  thrown  upward  toward  the  ceiling  and  is  not  allowed  to 
pass  directly  onto  the  animals  which  may  be  housed  in  the 
building.  The  fresh  air  is  diffused  through  the  room  and  the 
foul  air  passes  out  through  suitable  flues,  not  unhke  those  to 

be  described  later.  Cowls 
or  cupolas  are  used  in 
connection  with  outlet 
flues  and  are  designed  in 
such  a  manner  that  the 
winds  in  blowing  across 
them  produce  a  suction 
or  aspirating  effect  in  the 
flues. 

Temperature  System. 
The  principle  that  heated 
air  rises  is  the  theory 
basis  of  the  majority  of 
the  successful  ventilating 
systems  now  in  use.  The 
King  system,  named  after 
the  designer,  the  late 
Professor  F.  H.  King,  uses 
this  principle  as  well  as 
the  principle  that  foul 
air  is  heavier  than  pure 
air  when  both  are  at  the  same  temperature,  and  tends  to 
settle  towards  the  floor.  For  this  reason,  the  inlets  in  the 
King  system  discharge  pure  air  near  the  ceiling  and  the  out- 
let flues  receive  the  air  near  the  floor. 


V•M»MA:^.^;•.^<i>^^%■u':y:y^^?/;x.^••^■:^v■•^^■•.'.^^ 


Fig.  322j  Showing  one  method  of  ar- 
ranging the  outlet  flues  in  the  King  sys- 
tem. The  flues  may  be  brought  together 
to   form   a    common    outlet. 


FARM  SANITATION 


535 


r 


_/ 


rni 


7r 


Size  of  Inlets  and  Outlets.  Professor  King  advises  four 
square  feet  each  of  outtake  and  intake  flues  for  each  20  adult 
cows,  for  an  outlet  flue  20  feet  high;  or,  in  other  words,  36 
square  inches  of  cross-section  of  flue  should  be  provided  for 
each  cow.  If  the  outlet  flue  be  30  feet  high,  30  square  inches 
of  cross -section  will  be  sufficient.  To  be  successful,  there 
should  be  a  rather  large  number  of  intakes  and  few  out- 
takes.  The  outtakes  should  be  air-tight,  as  straight  as  pos- 
sible, and  as  smooth  as  practical  on  the  inside.  One  common 
cause  of  failure  of  this  system  of 
ventilation  is  incorrectly  con- 
structed outtakes  or  outlet  flues. 
Often  the  flues  are  made  of  one 
thickness  of  tongued  and  grooved 
lumber  which  dries  out  and  leaves 
open  cracks  which  prevent  the  flues 
from  working.  Again,  it  is  a  com- 
mon occurrence  to  find  that  the 
flues  are  made  with  many  sharp 
turns  which  restrict  the  flow  of 
air  through  them.  A  good  cupola, 
so  designed  as  to  produce  a  suction 
on  the  flues  connecting  into  it  when  the  wind  is  blowing, 
increases  the  efficiency  of  the  system  materially. 

Mechanical  Ventilation.  Mechanical  ventilation  is  prac- 
tically unknown  at  the  present  time  for  farm  buildings.  It 
consists  in  providing  fans  or  other  positive  means  of  forcing 
air  into  or  out  of  a  building,  and  is  considered  the  only 
modern  method  of  ventilation.  The  time  may  come  when 
it  will  be  considered  in  connection  with  farm  buildings.  All 
other  systems  depend  more  or  less  upon  varying  conditions  of 
wind  and  temperature,  which  cannot  be  controlled. 


Fig.  323.  Different  methods 
of  arranging  the  Inlet  flues  in 
the  King  system  of  ventila- 
tion. 


536  AGRICULTURAL  ENGINEERING 

QUESTIONS 

1.  Why  is  the  adequate  ventilation  of  farm  buildings  important? 

2.  Explain  what  is  meant  by  "standard  of  purity." 

3.  What  are  some  of  the  standards  recommended? 

4.  What  is  the  three-fold  purpose  of  ventilation? 

5.  How  much  air  is  breathed  per  hour  by  the  various  farm 
animals? 

6.  How  much  air  is  required  per  hour  for  each  of  the  various  farm 
animals  to  maintain  a  standard  of  96.7  per  cent  purity? 

7.  In  what  four  ways  may  ventilation  be  secured? 

8.  Describe  the  construction  and  discuss  the  efficiency  of  cloth- 
curtain  ventilators. 

9.  How  may  the  action  of  the  wind  be  used  in  securing  ventilation? 

10.  Describe  the  Sheringham  valve. 

11.  What  is  the  purpose  of  cowls  or  cupolas  on  ventilating  flues? 

12.  How  may  the  heating  of  air  be  used  as  a  basis  of  ventilation? 

13.  Describe  the  construction  of  the  King  system  of  ventilation. 

14.  What  are  the  possibilities  for  mechanical  ventilation? 

LIST  OF  REFERENCES 

Rural  Hygiene,  Henry  N.  Ogden. 

Sanitation,  Water  Supply,  and  Sewage  Disposal  of  Country  Houses, 
Wm.  Paul  Gerhard. 

Electric  Light  for  the  Farm,  N.  H.  Schneider. 

Disposal  of  Dairy  and  Farm  Sewage  and  Water  Supply,  Oscar  Erf. 
Bulletin  143,  Kansas  Agricultural  Experiment  Station. 

Sewage  Disposal  Plants  for  Private  Houses,  A.  Marston  and  F.  M. 
Okey.  Bulletin  VI,  Vol.  IV.,  Iowa  Engineering  Experiment  Station, 
Ames. 

Sanitation  and  Sewage  Disposal  for  Country  Homes,  William  C. 
Davidson,  Bulletin  No.  3,  Missouri  Engineering  Experiment  Station. 

Electric  Power  on  the  Farm,  Adolph  Shane.  Bulletin  25,  Iowa 
Engineering  Experiment  Station,  Ames. 

Ventilation,  F.  H.  King. 


PART  NINE— ROPE  WORK 

CHAPTER  LXXXV 

ROPE,  KNOTS,  AND  SPLICES 

A  practical  knowledge  of  the  correct  ways  of  tying, 
hitching,  and  spUcing  ropes  is  valuable  to  any  farmer.  His 
work  is  such  that  an  extended  use  must  be  made  of  ropes; 
and  such  knowledge  will  not  only  be  convenient  and  save 
time,  but  will  also  be  a  means  of  averting  accidents.  Only 
the  more  important  knots,  hitches,  and  spUces  will  be  dis- 
cussed. 

Kinds  of  Rope.  Mention  has  been  made  in  a  former 
chapter  concerning  the  various  kinds  of  rope  in  use  for 
transmitting  power.  The  rope  used  for  general  purposes 
about  the  farm  is  hemp  rope.  As  most  of  it  is  made  from 
Manila  hemp  imported  from  the  Philippine  Islands,  it  is 
generally  known  as  Manila  rope.  Cotton  rope  is  some- 
times used   for   halters  or  ties. 

In  making  rope,  the  fibers  are  first  spun  into  a  cord  or 
yarn,  being  twisted  in  a  direction  called  "righthand."  Sev- 
eral of  these  cords  are  then  made  into  a  ''strand"  by  being 
twisted  in  the  opposite  direction,  or  ''lefthand.'*  The  rope 
is  finally  made  up  of  three  or  four  of  these  strands  twisted 
"righthand,"  and  is  known  as  a  three-  or  a  four-strand  rope, 
depending  upon  the  number  of  strands  used.  The  four- 
strand  rope  is  constructed  on  a  core,  and  is  heavier,  more 
pliable,  and  stronger  than  the  three-strand,  in  any  given  size. 

Strength  of  Rope.  The  following  table  gives  the  strength 
and  weight  of  some  of  the  common  sizes  of  three-strand 
Manila  rope  when  new  and  free  from  knots.    The  smallest 

637 


538 


AGRICULTURAL  ENGINEERING 


size  of  pulley  upon  which  the  rope  should  be  used  is  also 
given.  The  working  strength,  or  the  greatest  load  the  rope 
should  carry  with  safety,  is  given  as  about  one-seventh  of  the 
breaking  load. 


Strength  of  different  sizes  of  three-strand  Manila  rope,  and 

size  of  pulley 

to  use. 

Diameter 

Weight  per 
100  lbs.  rope 

Safe  load 

Breaking  load 

Diameter  of 
pulley 

Inches 

Pounds 

Pounds 

Pounds 

Inches 

H 

3 

55 

400 

2 

5 

130 

900 

3 

H 

7.6 

230 

1620 

4 

Vs 

13.3 

410 

2880 

5 

H 

16.3 

520 

3640 

6 

Vs 

23.6 

775 

5440 

7 

1 

28.3 

925 

6480 

8 

Good  Knots.  The  three  qualities  of  a  good  knot  have  been 
stated  as  follows:  ''(I)  Rapidity  with  which  it  can  be  tied; 
(2)  its  abihty  to  hold  fast  when  pulled  tight;  and  (3)  the 
readiness  with  which  it  can  be  undone."  In  Kent's  Mechan- 
ical Engineer's  Pocket  Book  it  is  stated,  ''The  principle 
of  a  good  knot  is  that  no  two  parts  which  would  move  in 
the  same  direction  if  the  rope  were  to  slip 
should  lay  along  side  of,  and  touching,  each 
other." 

Parts  of  the  Rope.  For  the  sake  of  clear- 
ness in  the  discussion  of  knots  which  is  to 
follow,  the  student  should  understand  what 
is  meant  by  the  following  parts  of  a  rope : 

The  standing  part  is  the  long  unused 
part  of  the  rope,  as  represented  by  A, 
Fig.  324. 

The  hight  is  the  loop  formed  whenever  the  rope  is  turned 
back  upon  itself,  as  B. 


Fig.  324.       The 
parts   of  a    rope: 

A,  standing  part; 

B,  bight;  C,  loop; 
D.  end. 


ROPE  WORK 


539 


Fig.  325.     Square,  or  reef  knot. 


The  ejid  is  the  part  used  in  leading  the  rope,  as  D  in  the 
figure. 

A  loop  is  made  by  crossing  the  sides  of  a  bight,  as  C 

KNOTS 

The  square,  or  reef,  knot  is  one  of  the  commonest  knots 
used  in  tying  together 
ends  of  ropes  or  cords.  It 
is  the  knot  that  can  besti 
be  used  in  bandaging  or 
in  tying  bundles.  It  does 
not  sHp  and  is  quite  easily  untied.  In  tying  the  square 
knot,  the  ends  are  crossed,  bent  back  on  themselves,  and 
crossed  again,  making  the  outside  loop  pass  around  both  strands 
of  the  opposite  end.  As  usually  tied  both  ends  are  on  one 
side  as  shown  in  Fig.  325.     Then  it  will  not  slip. 

The  Granny,  or  False  Reef,  Knot.    If  the  ends  of  the  rope 
are  crossed  finally  in  the  wrong  direction,  the  result  is  not 

the  true  square  knot  but 

what    is    known   as    the 

granny  or  false  reef  knot, 

as  shown  in  Fig.  326.  This 

knot,  when  compared  with 

the  true  reef  knot,  illustrates  the  first  principle  of  knots. 

It  is  not  a  good  knot,  and  is  given  to  explain  this  principle. 

The  sheet  bend  or  weaver's  knot    is  universally  used 

by  weavers  in  tying  together  two  ends  of  threads  and  yarns, 


Fig.  326.     Granny  knot,  or  false  reef. 


Fig.    327.     Siieet    bend,    or   weaver's    knot. 


540 


AGRICULTURAL  ENGINEERING 


Fig.    328.     Bowline  knot. 


and  is  a  good  knot  inasmuch  as  it  is  very  secure,  can  be  rapid- 
ly tied,  and  easily  untied.  This  knot  is  tied  by  forming  a 
loop  with  one  rope  end,  as  shown  in  A,  Fig.  327,  and  then 

passing  the  other  end  back 
through  this  loop,  as  shown 
at  5.  When  pulled  tight 
the  knot  takes  the  form 
shown  at  C. 

The  bowline  knot  is  the 
best  knot  for  forming  a 
noose  or  loop 
which  will  not 
shp  when  under 
strain,  and  which  can  be  easily  untied.  Fig.  328 
shows  one  method  of  tying  the  bowKne.  In  tying 
this  knot  a  loop  is  formed  in  the  standing  parts  of 
the  rope,  as  shown  at  the  left  in  Fig.  328;  then  the 
end  of  the  rope  is  passed  through  this  loop  around 
the  rope  and  back  through  the  loop,  as  shown  at 
the  right.  This,  perhaps,  is  the  simplest  way  of 
tying  this  knot,  but  there  are  several  other  ways,  ^^^p   ^'^o*. 

The   halter,   slip,   or  running 

knot  is  used  where  it  is  desired 

that  the  rope  shall  bind,  as  on  a 

post  when   tying  a   halter  rope. 

This  knot  is  made  by  bending  the 

end  of  the  rope  over  itself  and 

carrying  it  around  the  standing  part 

of  the  rope  and  back  through  the 

loop  thus  formed. 

Often,  in  tying  a  halter  rope,  it  is  safer  to  use  a  bight  of 

the  rope  through  the  knot  and  then  pass  the  end  of  the  rope 

through  the  loop  so  formed,  as  shown  in  Fig.  330.    This 

knot  unties  somewhat  more  easily. 


329. 


Fig.     330.     Hitching 


ROPE  WORK 


541 


Fig. 


331.      Half 
hitch. 


HITCHES 

The  Half  Hitch.    The  half  hitch,  as  shown  in  Fig.  331, 
is  not  very  secure,  but  is  easily  made. 

The  clove  hitch,  as  shown  in  Fig.  332,  is 
more  secure  than  the  half  hitch.  It  is 
often  used  to  fasten  timbers  together. 

The  Timber  Hitch.  The  timber  hitch, 
(Fig.  333)  is  used  in  attaching  a  rope  to 
timber,  for  hauling,  and  similar  purposes. 
It  is  made  by  leading  the  end  of  the  rope 
around  the  timber,  then  around  the  standing  part,  and  back, 
making  two  or  more  turns  on  its  own  part.     The  strain  in 

the   rope    will  prevent  the  rope 
from  slipping. 

The  Blackwall  hitch  is  used  to 
attach  a  rope  to  a  hook;  and,  al- 
though simple,  it  holds  the  end  very 
securely.     See  Fig.  334. 

Two  Half  Hitches.  Two  half 
hitches  may  be  used  to  good  advantage,  for  they  prevent 
the  rope  from  slipping  under  any  strain.  They  are  easy  to 
form,  as  may  be  learned  from  Fig.  335. 
The  Sheepshank.  The  sheepshank 
is  used  in  shortening  a  rope.  It  is 
made  by  gathering  up  the  amount  to 
be  shortened  and  taking  a  half  hitch 
around  each  end,  as  shown  in  Fig. 
336.  If  it  is  desired  to  make  the 
knots  more  secure,  the  ends  of  the 
rope  may  be  passed  through  the  bights. 


Fig.   332.     Clove  hitch. 


Fig.     333.      Timber    hitch. 


FINISHING  THE  END  OF  A  ROPE 

Whipping.     Whipping  is  one  of  the  best  ways  of  prevent- 
ing a  rope  from  raveling;  and,  as  the  size  of  the  rope  is  not 


542 


AGRICULTURAL  ENGINEERING 


Fig.  334.  Black 
wall     hitch. 


materially  increased,  it  can  be  used  where  the 
rope  is  to  pass  through  pulleys  and  small 
openings.  Good,  stout  wrapping  cord  should 
be  used  for  the  whipping.  A  loop  of  cord  is 
laid  along  the  end  of  the  rope,  as  shown  at  A, 
Fig.  337.  The  loop  is  then  used  to  wrap  the 
rope,  allowing  the  side  of  the  loop  to  pass  over 
the  end  of  the  rope.  After  the  rope  has  been 
wrapped  for  a  sufficient  distance,  the  ends  of 
the  cord  are  pulled  tight  and  then  cut  off,  'as 
shown  at  B. 

Crowning  the  end  of  a  rope 
consists  in  unraveling  it  for  a 
short  distance,  usually  5  or  6 
inches;  then  knotting  the  strands 
and  turning  them  back  and  weaving  them 
into  the  rope.  This  increases  the  size  of  the 
rope  end,  but  makes  a  very  firm 
finish.  The  strands  are  first 
knotted  as  shown  at  A,  Fig. 
338.  Then  with  the  aid  of  a 
pointed,  smooth,  hardwood  stick 
the  loose  strands  are  woven  al- 
ternately over  and  under  the 
strands  in  the  rope.  When  passed  under 
three  or  more  strands  of  the  rope  in  this 
manner,  the  end  of  each  loose  strand  may  be 
cut  off.  To  prevent  kinks  and  to  make  a 
smoother  finish,  the  loose  strands  may  be 
slightly  untwisted  as  they  are  woven  into  the 
rope.  When  finished,  the  crown  should  have 
ehefpsha^nk!     the  appearance  of  D,  Fig.  338. 


Fig.     335.      Two 
half      hitches. 


ROPE  WORK 


643 


SPLICING 

The  Short  Splice.  The  short  splice  makes  the  rope  larger 
at  the  splice,  as  a  double  number  of  strands  are  woven  into 
the  rope  at  one  place. 
Thus  in  case  of  a 
three-strand  rope  the 
splice  is  six  strands 
thick  at  the  splice. 
This  splice  cannot  well 
be  used  where  the  rope 
is  to  run  over  pulleys. 

To  make  the  short  splice,  the  ends  of  the  rope  are  unlaid 
for  a  suitable  length,  which  will  vary  from  6  to  15  inches, 
depending  on  the  size  of  the  rope.  The  strands  are  then 
locked  together  by  tying  by  pairs  strands  from  opposite  ends 
of  the  rope,  with  a  simple  overhand  knot,  as  shown  at  B, 
Fig.  339.  After  tying,  the  strands  are  woven  into  the  rope 
in  each  direction  by  opening  the  rope  with  a  hardwood  pin 
and  tucking  them  under  every  other  strand  of  the  rope. 
This  tucking  may  be  repeated  two  or  more  times  and  the 
ends  then  cut  off,  leaving  a  splice  as  shown  at  D. 


Fig 


Whipping. 


Crowning. 


The  Long  Splice.    The  long  splice  is  not  so  bulky  as  the 
short  splice,  and  should  be  used  where  the  rope  is  to  run 


544 


AGRICULTURAL  ENGINEERING 


over  pulleys.  It  is  so  made  that  ends  of  the  strands  are 
joined  at  different  places,  making  the  largest  number  at  any- 
one place  only  one  greater  than  the  number  of  strands  in  the 


Fig.   339.      Short  splice. 


rope.  Thus  with  a  three-strand  rope  the  number  of  strands 
through  the  splice  is  four.  In  making  the  long  spHce,  a  much 
longer  length  of  each  end  of  the  rope  is  unlaid.  For  a  ^-inch 
rope,  this  should  be  about  18  inches;  for  a  J^-inch  rope,  24 
inches;  for  a  ^-inch  rope,  36  inches;  for  an  inch  rope,  36 


Fig 


Long  splice,  three-strand  rope. 


inches  and  so  on.  After  unlaying  the  rope  ends  for  the  proper 
distance,  they  are  locked  together  as  shown  at  A,  Fig.  340. 
By  unlaying  one  strand  from  each  of  the  rope  ends  and  filling 


ROPE  WORK 


646 


in   with   one  of  the  loose  strands,  bring  the  splice  into  the 
form  shown  at  B.     Then  tie  the  strands  and  weave  the  loose 

ends  into  the  rope  as 
in  the  case  of  the 
short  splice,  as  shown 
at  C,  finishing  the 
sphce  as  shown  at  D. 
The  Side  Splice. 
The  end  of  a  rope 
may  be  joined  into 
the  side  of  the  rope 
in  a  similar  way,  as 
3"**'  '^  '^       is  shown  in  Fig.  341. 

Rope  Halters. 
Rope  halters  can  be 
conveniently  made  in  a  variety  of  forms,  as  shown  in  A,  B, 
and  C,  in  Fig.  342.  The  size  of  these  halters  will  depend 
upon  the  size  of  the  animals  for  which  they  are  intended. 


Fig, 


S'ide  splice. 


Fig.    342.      Rope   halters. 


Their  making  does  not  require  the  use  of  any  new  princi- 
ples other  than  those  discussed. 


QXJESTIONS 

1.  To  what  practical  use  may  a  knowledge  of  knots  be  put? 

2.  Of  what  materials  are  ropes  made? 


546  AGRICULTURAL  ENGINEERING 

3.  Describe  the  making  of  a  rope. 

4.  What  size  of  rope  should  be  used  for  a  500-pound  load? 
A  1000-pound  load? 

5.  What  are  three  qualities  of  a  good  knot? 

6.  What  is  the  most  important  principle  of  the  knot? 

7.  Name  and  describe  the  parts  of  a  rope. 

8.  Describe  the  following  knots,  and  explain  where  they  are  useful : 
The  square  or  reef  knot;  the  granny  knot;  the  weaver's  knot;  the  bow- 
line knot;  the  halter  or  slip  knot. 

9.  Describe  the  following  hitches  and  their  use:  The  half  hitch; 
the  clove  hitch;  the  timber  hitch;  the  Blackwall  hitch;  two  half  hitches. 

10.  What  is  the  sheepshank  used  for?     Describe  how  it  is  made. 

1 1 .  Explain  how  the  end  of  a  rope  may  be  finished  by  whipping.     By 
crowning. 

12.  Describe  the  making  of  a  short  splice.     The  long  splice.     The 
eide  splice. 

13.  Describe  how  three  styles  of  halters  may  be  made. 


INDEX 


Acetylene  plant,  515;  cost  of, 
519;  generator,  517;  produc- 
tion of  gas,  517. 

Agricultural  Engineering,  de- 
fined, 13. 

Air,  amount  breathed  by  ani- 
mals, 532;  amount  in  gas 
mixtures,  350;  standard  of 
purity  of,  531. 

Air  pressure  water  system,  494. 

Alfalfa,  under  irrigation,  119. 

Alfalfa  harrow,  217. 

Ammeters,  358. 

Angle  of  incidence  of  sun's 
rays,  507. 

Angle  of  traces,  331. 

Areas,  computing,  34;  problems, 
37. 

Arrows,  21. 

Ash  wood,  use  in  tools,  196. 


Babbitting  boxes,  192. 

Ball  bearings,  191. 

Balloon  frame,  for  houses,  455. 

Barns,  dairy,  436;  horse,  442; 
round,  449. 

Barn  framing,  445. 

Basin  method  of  irrigation,  132. 

Bathroom  fixtures,  499. 

Batteries,  358. 

Beams,  strength  of,  406;  form- 
ula for,  408. 

Bearing  of  a  line,  53;  of  a 
plow,  201. 

Bearings,  ball,  191;  adjust- 
ment of,  193;  harrow,  218; 
ring  oiling,  191;  roller,  191; 
self-aligning,  190. 

Beech  wood,  196. 


Belting,  320;  canvas,  321; 
horsepower  of,  320;  lacing 
of,  322;  leather,  321;  rubber, 
321. 

Bench  marks,  43,  49. 

Bending  moment,  406. 

Berm,  104. 

Bessemer  steel,  197. 

Binder,  grain,  244;  adjustment, 
248;  causes  of  failure  to  tie, 
248;  engine  drive,  246,  269; 
operation  of,  246;  selection, 
244;  size,  244;  tongue  truck, 
246. 

Birch  wood,  for  machines,  196. 

Blower,  ensilage,  275;  thresher, 
280. 

Boiler,  steam,  376;  capacity 
of,  379;  locomotive,  378; 
management  of,  383;  return 
flue,  379;    vertical,  377. 

Boiler  feeder,   382. 

Border  method  of  irrigation, 
133. 

Boxes,  of  machines,  190;  bab- 
bitting, 192;  enclosed  wheel. 
191. 

Brick,  building,  410. 

Brick  roads,  165. 

Bridges,  concrete,  177;  design 
of,  175;  foundation  for,  177; 
importance  of,  175 ;    size,  175. 

Bridging,  456. 

Brooks,  as  farm  water  supply, 
484. 

Bubble  tube,  44. 

Buildings,  farm,  capital  invest- 
ed in,  395;  heating,  525; 
lighting,  506;  location  of, 
395;    ventilation  of,  531. 


548 


INDEX 


Cable  transmission,  324. 

Calcium  carbide,  515. 

Canals,  122. 

Candle,  standard,  511. 

Canvas  belting,  321. 

Capillary  water,  57. 

Carburetors,  345,  351. 

Carriers,  hay,  271. 

Cart,  harrow,  213. 

Cast  iron,  as  machine  material, 
196. 

Cast  steel,  197. 

Catch  basin,  99. 

Cement,  Portland,  410. 

Center,  dead,  387. 

Cesspool,  501. 

Chaining,  23,  24. 

Check  method  of  irrigation,  131. 

Chilled  cast  iron,  197. 

Clay  roads,  153. 

Clutch,  on  tractors,  372,  392. 

Coefficient  of  friction,  188,  189. 

Combustion  of  gases,  344,  350. 

Compass,  53. 

Component  forces,  314. 

Compound  engines,  386. 

Compression,   352. 

Concave,  279. 

Concrete,  411;  proportions  for, 
412;    reinforcement  of,  412. 

Concrete  roads,  166;  bridges, 
177. 

Connecting  rod,  385. 

Contour  maps,  52. 

Corn  harvesters,  251;  binders, 
252;  buskers,  256;  pickers, 
254;  shocker,  254;  shredder, 
256;    sled  cutters,  251. 

Corn  planters,  231;  adjust- 
ment, 236;  conveniences, 
235 ;  dropping  mechanism, 
226;  essentials  of,  231;  fur- 
row-openers, 234;  graded 
seed  for,  238;  wheels,  234; 
variable  drop,  233. 

Correction  lines,  39. 

Cow  ties,  440. 

•Crank  shaft,  385. 


Crowning  a  rope,  542. 

Crown  sheet,  378. 

Cultivators,  237;  construction, 
238;  balance  frame,  240; 
disk,  242;  guiding  devices, 
241;  seats,  241;  selection 
of,  237;  surface,  242;  walk- 
ing, 238;     wheels,  240. 

Culverts,  175;  concrete,  178; 
design  of,  175;  importance 
of,  175;    pipe,  178;    size,  175. 

Cutters,  ensilage,  273;  con- 
struction, 276;  elevating  me- 
chanism, 275;  mounting,  275; 
selection  of,  276;  self-feed, 
275;    types,  273. 

Cylinder,  488;    threshing,  278. 

Dairy  barns,  436;  construction 
details,  437;  essentials  of, 
436;    types,  436. 

Datum,  42. 

Dead  center,  387. 

Declination  of  the  needle,  53. 

Deep-tilling  machine,  206. 

Deere,  John,  181. 

Differential,  393. 

Disk  harrow,  213. 

Disk  plow,  204. 

Ditches,  cost  of  digging,  101; 
digging  for  tile,  86,  93;  fill- 
ing, 96;  grading,  89;  open, 
103. 

Ditching  machines,  87. 

Draft,  of  plows,  204;  principles 
of,  330. 

Drainage,  56;  benefits  of,  61; 
districts,  108;  history  of,  56; 
land  drainage,  86;  lands 
needing,  58;  open  ditch,  103; 
systems  of,  67;  underdrain- 
age,  59. 

Drainage  districts,  108;  assess- 
ments, 109;  defined,  108; 
laws  for,  108;    survey  of,  109. 

Drainage  engineer,  64. 

Drainage  system,  67. 

Drainage  wells,  100. 


INDEX 


549 


Drawing  instruments,  28. 

Drills,  225;  adjustment  of,  229; 
force  feeds,  227;  furrow- 
openers,  225;  horse  lift,  229; 
press  drill,  228;  seed  tubes, 
228;    selection  of,  228. 

Dynamometers,  317. 

Dynamos,  358. 

Earth  roads,  147;  construction, 
147;  crown,  149;  drainage 
of,  147;  extent,  147;  grades, 
151;     maintenance,  150. 

Efficiency  of  lamps,  513;  of  a 
machine,  186. 

Elasticity,  defined,  404. 

Electric  light,  520;  cost  of, 
524;  plant,  521;  selection  of 
plant,  522;  source  of  power, 
521. 

Electrical  terms,  522. 

Elements  of  machines,  186. 

Elevation  of  a  point,  42. 

Elevators,  ensilage,  275;  por- 
table farm,  287. 

Energy,  kinds  defined,  313. 

Engineer,  drainage,  64. 

Engineering,  defined,   13. 

Engine  gang  plows,  208. 

Engines,  gasoline  or  oil,  344; 
measuring  power  of,  316: 
operation  of,  350;  steam, 
876,   385;     tractors,  370,  389. 

Ensilage  machinery,  273. 

Equilibrium,  defined,  402. 

Essentials  of  a  machine,  187. 

Eveners,  334;  four-,  five-,  and 
six-horse,  336;  placement  of 
holes,  334;  plain,  337;  three- 
horse,  335. 

Factor  of  safety,  405. 

Fanning  mills,  282. 

Farmhouse,  the,  451;  con- 
structing, 455;  features  of 
construction,  451;  location 
of,  451;    plan  of,  452. 

Farm  machinery,  180. 


Farm  mechanics,  defined,  15. 

Farm  sanitation,  480. 

Farm  structures,  395. 

Feed  mills,  298. 

Feed  water  heater,  382. 

Fields,  leveling,  52. 

Fixtures,     bathroom,     499; 

plumbing,  497. 
Flagstaff,  21. 
Flooding  method  of  irrigation, 

131. 
Flow  of  water,  in  ditches,  105; 

in  pipes,  491;    in  tile,  78. 
Foaming  in  boilers,  383. 
Foot  pound,  defined,  314. 
Force,  action  of,  402;    defined, 

314. 
Forks,  hay,  270. 
Friction,  coefficient  of,  188,  189; 

defined,    187;     of   rest,   188.; 

rolling,  188. 
Friction  gearing,  325. 
Fuels,  for  engines,  344. 
Full  frame,  445,  455. 
Furnaces,  for  boilers,  377;    for 

houses,    526. 
Furrow    method    of   irrigatioa, 

133.  ' 
Fusible  plug,  382. 

Gang  plows,  201;    engine,  208. 

Gas  mixture  for  engines,  350; 
testing,  352. 

Gasoline  engines,  344;  classes, 
344;  estimating  horsepower 
of,  367;  four-stroke  cycle, 
346;  fuel  for,  344;  operation 
of,  350;  for  pumping,  486; 
selection  of,  361;  testing, 
366;  two-stroke  .cycle,  347; 
types,  345;  use  on  binders, 
246,  364. 

Gasoline  lamps,  514. 

Gas  tractors,  370. 

Gauge,  cocks.  380;  glass,  381; 
pressure,  381. 

Gearing,  for  transmitting  pow- 
er. 324;    traction,  373,  393. 


650 


INDEX 


Governor,  engine,  387. 
Graders,   grain,  282. 
Grading  tilfe  drains,  73,  89. 
Grain,  under  irrigation,  118. 
Graphite,  as  a  lubricant,  189. 
Gravel  roads,  154;   binder,  155; 

cost    of,    158;     drainage    of, 

156;     maintenance    of,    158; 

surface  construction,  156. 
Grease  cups,   192. 
Grip,    of    horse,    influence    on 

draft,  331. 
Gunter's  chain,  18. 
Gunter's  chain  measure,  19. 

Halters,  rope,  545. 

Harrow  attachment  for  plows, 
219. 

Harrows,  211;  cart  for,  213; 
construction  of,  212,  215; 
disk,  213;  smoothing,  211; 
spring-tooth,  213. 

Harvester,  corn,  251;  grain, 
244. 

Hay  machinery,  barn,  270; 
field,  258. 

Heating  systems,  525 ;  fur- 
naces, 526;     stoves,  525. 

Hickory  wood,  qualities  and 
uses,  196. 

Hillside  plow,  207. 

Hitch,  length  of,  influence  on 
draft,   332. 

Hitches,  541. 

Hog  houses,  414;  individual, 
417;    large,  419. 

Horse,  amount  of  service  from, 
329;  as  a  motor,  327;  capa- 
city of,  328;  draft,  330;  size 
of  teams,  329;  weight,  etc. 
of,  influence  on  draft,  330. 

Horse  barns,  features  of  con- 
struction,  442. 

Horsepower,  314;  estimating, 
engines,  316,  366. 

Hot  water  heating  system,  528. 

Husker,  corn,  256. 


Hussey,  Obed,  181. 
Hydrostatic  water,  57. 

Ignition,  in  oil  engines,  354; 
jump-spark  system,  357; 
make-and-break  system,  355. 

Implement,  defined,  186. 

Implement  house,  473;  details 
of  construction,  474;  loca- 
tion, 473;    size,  473. 

Incandescent  lamp,  521. 

Injector,  382. 

Instruments,  for  leveling,  42; 
for  measuring,  18. 

Iowa  silo,  469. 

Iron,  cast,  196;    wrought,  197. 

Irrigation,  111;  amount  of  wa- 
ter  used  in,  117;  applying 
water  in,  129;  crops  grown 
by,  118;  history  of,  112;  pre- 
paring land  for,  130;  pur- 
poses of,  113;  sewage  dis- 
posal by,  138;  supplying 
water  for,  122. 

Irrigation  culture,  115;  in 
humid  regions,  136. 

Jacks,  lifting,  287. 
Journal,  190. 
Jump-spark  ignitors,  357. 

Kerosene  lamps,  511. 

Knots,    essentials    of    a    good, 

538  f    kinds,   539. 
Knotter,  binder,  248. 
Kutter's  formula,  105. 

Labor,  farm,  influence  of  ma- 
chinery on,  181;  of  inconven- 
ient buildings  on,  395. 

Lakes,  as  farm  water  supply, 
484. 

Lamps,  efficiency  of,  513;  gas- 
oline, 514;    kerosene,  511. 

Land  rollers,  220. 

Laundry,  in  farmhouse,  454. 

Laying  out  the  farm,  396. 

Leaks,  in  oil  engines,  353. 


INDEX 


551 


Leather  belting,  321. 
Lettering,    32. 

Level,  45;    adjustments  of,  46. 
Leveling,    definition    of   terms, 

42;   practice,  49;   tile  drains, 

73. 
Light,  unit  of,  511. 
Lighting  systems  for  buildings, 

acetylene,  515;    development, 

510;     laipps,    511;     natural, 

506;    electric,  520. 
Lime,  for  motar,  410. 
Linear  measure,  19. 
Liners,  193. 
Link  belting,  323. 
Loaders,  hay,  266. 
Locomotive  boiler,  378,  528. 
Lubrication,     189;      choice    of 

lubricant,  189. 

McCormick,  Cyrus  W.,  181. 

Macadam  roads,  16-0;  bitumi- 
nous, 163. 

Machine,  .  defined,  186;  ele- 
ments of,  186. 

Machine  shed,  473. 

Machinery,  farm,  180;  binder, 
239;  care  of,  309;  corn 
harvester,  252 ;  corn  shellers, 
299;  definitions  and  princi- 
ples, 186;  elevators,  287; 
ensilage,  273;  fanning  mills, 
282;  feed  mills,  298;  hay, 
258;  infiuence  of,  181;  in- 
troduction of,  180;  manure 
spreaders,  292;  motors,  313; 
threshing,  278;  spraying, 
303;    windmills,  339. 

Magnetos,  358. 

Manure  spreaders,  292. 

Malleable  iron,  for  machines, 
197. 

Maps,  contour,  52;  final,  76; 
preliminary  survey,  66. 

Map  making,  28. 

Maple  wood,  qualities  of,  196. 


Markets,   influenced  by   roads, 

143. 
Materials,    mechanics    of,    402, 

406;  used  in  machinery,  195. 
Measurement    of    power,    316; 

of  water,  134. 
Measuring,      18;      instruments 

for,  20;  tables  for,  19. 
Mechanics,  defined,  15. 
Mechanics    of    materials,    402, 

406. 
Meridian,  guide,  39;   principal, 

38. 
Metes  and  bounds,  surveys  by, 

40. 
Modulus  of  rupture,  408. 
Modulus  of  section,  407. 
Moment  of  a  force,  402. 
Monuments,  40. 
Motors,    classification   of,  344; 

farm,  313;  horses  as,  327. 
Mowers,  258;  adjustment,  262; 

construction,  258;   size,  258; 

types,  258. 

Newbold,  Chas.,  180. 
Notes,  field,  24,  50. 


Oak,  as  material  for  machines, 

196. 
Oil  cups,  192. 
Open  ditches,  103;  capacity  of, 

104;     construction     of,    103; 

cost   of,    104;    disadvantages 

of,  104. 
Orchard  irrigation,  121. 


Pacing,  23. 

Perry  pneumatic  water  supply 
system,  495. 

Pine,  for  machines,  196. 

Pipes,  water,  491;  flow  of  wa- 
ter in,  492;  sizes,  491;  sys- 
tems, 492. 

Plank  frame  for  barns,  445. 

Planter,  corn,  231. 

Plastering,  458. 


552 


INDEX 


Plows,  199;  adjustment,  200; 
construction,  200;  disk,  204; 
draft  of,  204;  engine  gang, 
208;  gang,  201;  harrow  at- 
tachment for,  219;  hillside, 
207;  selection  of,  199;  size, 
199;  sulky,  201;  types  of, 
199. 

Plumb  line,  43. 

Plumbing,  for  houses,  497;  fix- 
tures, 497. 

Plungers,  for  pumps,  489. 

Poncelet's  formula,  79. 

Population  on  farms,  183. 

Poplar  wood,  qualities  and 
uses,  196. 

Potatoes  under  irrigation,  120. 

Poultry  houses,  425;  construc- 
tion details,  426';  location, 
425;  size,  425;  types,  432. 

Power,  defined,  314;  for  light- 
ing plant,  521;  for  pumping, 
486;  from  horses,  327;  meas- 
urement of,  316;  required 
for  machinery,  361;  trans- 
mission of,  320. 

Power  mills,  298,  340. 

Preliminary  survey,  64. 

Pressure  gauge,  381. 

Prime  movers,  313. 

Profile,  leveling,  49;  grade,  74. 

Prony  break,  316. 

Pumps,  487;  important  fea- 
tures of,  488. 

Pumping  plant,  486. 

Pumpinng  water,  cost  of  with 
engine,  363;  for  irrigation, 
125. 

Pulleys,  322;  calculating  speed 
of,  323. 

Purlines,  445. 

Pulverizers,  221. 

Quadrants,  for  transmitting 
power,  324. 

Radiation,  estimating,  529. 
Radiators,  526.  529. 


Rakes,  sweep,  268;   sulky,  259; 

side  delivery,  260. 
Range  of  townships,  39. 
Range  pole,  21. 
Rating,  of  tractors,  392. 
Rectangle,  area  of,  34. 
Reinforcement      of      concrete, 

412. 
Repair  of  machinery,  309. 
Reservoirs,  for  irrigation,  123; 

home  water  supply,  493. 
Resultant,  defined,  314. 
Resurveys,  40. 
Reversible  plow,  207. 
Road  drag,  150,  173. 
Road     grader,     97;     elevating, 

169;   scraping,  168. 
Road    machinery,  167;  classes, 

167;   scrapers,  167. 
Roads,    141;  benefits   of    good, 

142;    brick,    165;    clay,    153; 

earth,    147;    extent    of,    141; 

gravel,    154;    history   of,  14; 

requisites      of      good,      145; 

sand,     153;     sand-clay,    153; 

scrapers  for,  167;  stone,  160. 
Road  rollers,  170. 
Road  stone,  160;  testing,  161. 
Rock  crushers,  172. 
Roller  bearings,  191. 
Rollers,   for  roads,  horse,  170; 

land,   220;    power,   171;    tan- 
dem, 171. 
Rope  transmission,  323. 
Round  barns,  449. 
Rubber  belting,  321. 
Run-off,  computing,  80. 


Safety  valve,  381. 

Sand,  for  building,  411. 

Sand-clay  roads,  153. 

Sand  roads,  153. 

Sanitation,  480. 

Scrapers,  for  disk  harrows,  218; 

road,  167. 
Sections  of  townships.  39. 


INDEX 


553 


Seeders,  end  gate,  224;  hand, 
223;  seed-box  broadcast,  224; 
utility  of,  223;  wheelbarrow, 
224. 

Self-aligning  bearing,  190. 

Septic  tank,  501;  construction 
of,  504. 

Sewage  disposal,  principles  of, 
502;  by  irrigation,  114,  138; 
systems  of,  501. 

Shafting,  325. 

Shawver  barn  frame,  446,  448. 

Sherringham  valve,  534. 

Shredders,  256. 

Shop,  farm,  477. 

Side  draft,  overcoming,  337. 

Silos,  461;  essentials,  463;  lo- 
cation, 461;  masonry,  468; 
size,  461;  wood,  465. 

Silt  basins,  99. 

Sled  corn  cutters,  251. 

Slings,  hay,  271. 

Soils,  improved  by  drainage, 
61;  kinds  of,  59. 

Splices,  543. 

Spraying  machinery,  303. 

Spraying  method  of  irrigation, 
134. 

Springs,  as  water  supply,  483. 

Spring-tooth  harrow,  213. 

Stackers,  hay,  269;   straw.  280. 

Stalls,  cow,  440;  horse,  443. 

Standard  of  purity  of  air,  531. 

State  Highway  Commission, 
178. 

Statics  defined,  402. 

Steam  boiler,  376;  accessories, 
380;  capacity  of,  379;  func- 
tions of,  377;  management, 
388;  principle  of,  376;  types, 
377. 

Steam  engines,  376,  385;  kinds, 
386;  principle  of,  385. 

Steam,  formation,  377;  quality 
of,  380. 

Steel,  Bessemer,  197;  cast,  197; 
mild,  197;  soft  center,  198; 
tool.  198. 


Stone,  building,  409. 

Stone  roads,  160;  construction 
of,  162;  cost  of,  165;  main- 
tenance of,  165. 

Stoves,  525. 

Strength  of  materials,  402,  406. 

Stress,  defined,  403;  kinds  of, 
403. 

Subirrigation,  133. 

Subsurface  packer,  220. 

Suction  of  plows,  200. 

Sugar  beets  under  irrigation, 
120. 

Sulky  plows,  201;  adjustments 
of,  203. 

Sunlight  as  a  sanitary  agent, 
506. 

Surface  measure,  19. 

Survey,  defined,  16;  prelimi- 
nary, 64. 

Surveying,  agricultural,  16; 
divisions  of,  17;  problems,  26. 

Surveyor's  measure,  20;  uses 
of,  16. 

Sweep  rakes,  268. 

Tanks,  water,  493. 

Tapes,  20;  care  and  use  of,  22. 

Teams,  size  of,  329. 

Tedder,  hay,  267. 

Telford  roads,  160. 

Temperature  system  of  ventila- 
tion, 534. 

Tests,  of  concrete,  411 ;  engines, 
316,  36^6;  horse,  328. 

Threshing  machinery,  278. 

Tile,  blinding,  94;  cement,  92; 
inspection  of,  94;  laying,  92; 
roots  of  trees  in,  100;  select- 
ing, 91. 

Tile  drains,  capacity  of,  78 
cause  of  flow  in,  78;  construe 
tion  of,  96;  cost  of,  101 
depth,  67;  digging  ditches 
86;  distance  apart,  68;  filling 
96;  outlet  of,  98;  size  of  lat 
erals,  84;  staking  out,  71 
systems  of,  69. 


554 


INDEX 


Tongue  truck,  338;  for  harrows, 
218. 

Tool,  defined,  186. 

Tool  shop,  477. 

Topographical  signs,  31. 

Towers,  water,  493;  windmill, 
342. 

Township,  division  and  num- 
bering, 38;  sections  of,  39. 

Traces,  proper  angle  of,  331. 

Tracks,  hay,  272. 

Tractor,  steam,  389. 

Transit,  54. 

Transmission  of  power,  320. 

Transportation,  cost  of,  142. 

Transport  truck,  219. 

Trapezium,  area  of,  35. 

Trapezoid,  area  of,  35. 

Triangles,  area  of,  34;  trans- 
mission of  power  by,  324. 

Trucks,  transport,  219. 

Turning  point,  52. 

Ultimate  strength  of  materials, 

404. 
Underdrainage,  59. 
United   States   system  of  land 

survey,  38. 

Valve  action  in  oil  engines,  359. 
Valves,  for  pumps,  489;  safety, 

381. 
Ventilation  of  farm  buildings, 

531;    influence  of  wind,  533; 

mechanical,  535;  purpoac^  of, 

31;  temperature  system,  534. 
Ventilator,  cloth  curtain,  533. 
Vertical  boiler,  377. 


Wages,  influence  of  farm  ma- 
chinery on,  182. 

Warm-air  furnace,  526. 

Waste  bank,  104. 

Water,  capillary,  57;  control  of, 
111;  duty  of,  56;  hydrostatic, 
57;  measurement  of,  134;  reg- 
ulation of  soil  water,  56;  re- 
quired for  crops,  115;  used  in 
irrigation,  117. 

Water  level,  43;  laying  tile  bv, 
89. 

Water  pipe,  491;  flow  of  water 
in.  491;  sizes,  491;  systems, 
492. 

Water  supply,  480. 

Water  wheels,  487. 

Weigher,  280. 

Weir,  134. 

Wells,  480. 

Whipping  a  rope,   541. 

Windmills,  339;  construction, 
341;  development,  339;  power 
of,  341;  regulation,  341;  size 
of,  340;  towers,  342;  tj^pes  of, 
340;  utility  of,  339,  486. 

Windows,  "design  of,  5-08;  loca- 
tion of,  507;  size  of,  508. 

Wing  joist  barn  frame,  446. 

Wire  rope  transmission,  324. 

Wood,   as   a   material   for   ma- 
chines, 195. 
Work,  defined,  186,  314. 
Working  stress,  defined,  404. 
Wrought  iron,  197. 
Wye  level,  46. 


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A.  D.  WILSON, 

Superintendent  of  Farmers'  Institutes  and  Extenfiioa, 

Minnesota  College  of  Agriculture, 

and 

C.  W.  WARBURTON, 

Agronomist,  U.  S.  Department  of  Agriculture. 


544  pages,  162  illustrations,  cloth,  $1.50  net. 

The  aim  of  this  book  is  to  present  the  peculiarities  of  each  of  the 
various  classes  and  varieties  of  farm  crops,  the  handling  of  the  soil, 
selections  of  seed,  and  general  crop  management.  The  book  covers  the 
cereals,  including  com,  wheat,  oats,  rye,  barley,  etc.;  forage  crops,  in- 
cluding hay  grasses,  clover,  alfalfa,  cowpeas  and  other  legumes;  how  to 
make  good  meadows  and  pastures,  and  the  art  of  hay  making,  etc.;  root 
crops;  sugar  crops;  fiber  crops,  including  cotton,  flax,  hemp;  tobacco, 
potatoes,  in  fact  every  farm  crop  of  any  importance  is  discussed.  The 
mtroductory  chapters  are  devoted  to  the  general  classification  of  farm 
crops  and  their  uses  and  relative  importance,  and  reviews  the  subject 
of  how  plants  gi-ow.  The  concluding  chapters  discuss  the  theory  and 
practice  of  crop  rotation  and  weeds  and  their  eradication.  A  hst  of 
the  best  supplementary  reading,  including  farmers  bulletins,  is  given  at 
the  close  of  each  chapter.  The  style  is  easy,  subject  matter  weP 
arranged  and  vital,  and  the  book  is  of  excellent  mechanical  mfiko 
up  t&oughout. 


BEGINNINGS  IN  ANIMAL  HUSBANDRY 

By  CHARLES  S.  PLUMB,  Professor  of  Animal  Husbandry,  College 

of  Agriculture,  Ohio  State  University. 

395  pages.  217  illustrations,  cloth,  $1.25  net. 

Beginnings  in  Animal  Husbandry  is  the  only  book  published  that 
is  specially  designed  to  meet  the  needs  of  students  in  Animal  Husbandry 
courses  in  secondary  schools.  Among  the  subjects  discussed  are:  The 
Importance  of  Animal  Husbandry;  Breeds  of  Horses,  Cattle,  Sheep 
and  Swine;  Animal  Type  and  Its  Importance;  Reasons  and  Methods 
in  Judging  Live  Stock;  Points  of  th©  Horse;  Judging  Horses,  Cattle, 
Sheep  and  Swine,  etc.;  Heredity:  Its  Meaning  and  Influence;  Selection 
and  Its  Importance;  Pedigrees  and  Their  Values;  Suggestions  to  Young 
Breeders;  Composition  of  Plants  and  Animals;  Influence  of  Foods  on 
the  Body;  Feeding  Standards,  Origin  and  Use;  How  to  Calculate  a 
Ration;  Coarse  Feeds  and  Their  Values;  Concentrated  Feeds  and  Their 
Value;  Care  of  Farm  Animals;  Poultry:  Types  and  Breeds,  Judging, 
Feeding;  Eggs  and  Incubation;  Poultry  Houses.  Topics  for  discus- 
sion and  suggestions  for  observation  and  apphcation  are  included  at 
the  close  of  each  chapter. 

SOILS  AND  SOIL  FERTILITY 

By  A.  R.  WHITSON,  Professor  of  Soils  and  Drainage,  and  H.  L. 

WALSTER,  Instructor  in  Soils,  of  the  University  of 

Wisconsin. 


315  pages,  well  illustrated,  cloth,  $1.25  net. 

No  other  book  on  Soils  presents  the  relation  of  the  soil  to  the 
production  of  crops  in  so  clear  and  agreeable  a  manner  as  this.  There 
are  chapters  on  the  following:  Conditions  Essential  to  Plant  Growth, 
Origin  and  Classification* of  Soils;  Primary  Relations  of  Soil  and  Plant; 
Nitrogen;  Phosphorus  and  Potash;  Soil  Analysis;  Farm  Manure;  Com- 
mercial Fertilizers;  Physical  Properties  of  Soils;  Water  Supply;  Tem- 
perature and  Ventilation  of  Soils;  Drainage;  Erosion;  Tillage;  Humus; 
Relation  of  Crops  to  Climate  and  Soil;  Soils  of  the  United  States; 
Management  of  Important  Types  of  Soil;  Dry  Farming.  Explicit 
language  and  the  avoidance  of  technical  matter  make  the  book  ideal  for 
beginners  in  this  subject.  A  well-chosen  set  of  fundamental  labora- 
tory exercises  and  demonstrations,  with  complete  directions,  is  included. 


POPULAR  FRUIT  GROWING 

By  SAMUEL  B.  GREEN,  late  Professor  of  Horticulture  and  Forestry, 
University  of  Minnesota. 

300  pages,  120  illustrations,  cloth,  $1.00  postpaid. 

This  book  covers  the  factors  of  successful  Fruit  Growing,  with 
lists  of  fruits  adapted  to  each  state;  Orchard  Protection;  Injurious 
Insects  and  Diseases;  Spraying;  Harvesting  and  Marketing  Methods; 
Propagation  of  Fruits;  etc.  A  very  popular  book  for  schools  and  col- 
leges. A  new,  revised  edition  by  Le  Roy  Cady,  Professor  of  Horticul- 
ture, University  of  Minnesota,  is  just  out. 


VEGETABLE  GARDENING 

By  SAMUEL  B.  GREEN,  late  Professor  of  Horticulture  and  Forestry, 
University  of  Minnesota. 


252  pages,  profusely  illustrated,  cloth,  $1.00, 


A  manual  on  the  growing  of  vegetables  for  home  use  and  for  the 
market.  The  immense  sale  of  this  book  to  farmers  and  gardeners,  and 
its  wide  adoption  for  class-room  work  in  agricultural  schools  and  col- 
leges, prove  it  to  be  the  standard  work  published  on  this  subject.  This 
is  the  12th  revised  edition.  We  have  a  paper  covered  edition  of  this 
book  which  sells  for  50c. 


DAIRY  LABORATORY  GUIDE 

By  G.  L.  MARTIN,  Professor  of  Dairying,  North  Dakota  Agricultural 

College. 


140  pages,  illustrated,  cloth,  50c. 


This  laboratory  manual  offers  a  carefully  organized  series  of  exer- 
cises covering  the  principles  of  modem  dairy  {)ractice,  with  sugges- 
tions for  their  practical  application.  It  covers  the  Production  and  Care, 
Testing,  Manufacture,  and  Marketing,  of  Dairy  Products.  An  indis- 
pensable guide  for  classes  in  Dairying  and  for  Creamery  men. 


SILOS:  CONSTRUCTION  AND  SERVICE 

By  M.  L.  KING,  formerly  Silo  Expert,  Iowa  State  College,  and  Orig- 
inator of  the  Iowa  Silo. 


100  pages,  well  illustrated,  cloth,  50c. 


There  is  no  recent  American  book  on  silo  building,  and  none  of 
any  date  that  covers  the  many  types  of  silos  now  in  use  and  gives 
details  of  their  construction.  Mr.  King  here  presents  to  the  intended 
builder  the  principles  of  silo  construction,  and  the  advantages  and  dis- 
advantages of  each  type;  but  more  particularly  he  gives  the  actual 
method  of  construction,  with  the  main  points  of  silo  management. 


RULES  OF  ORDER  FOR  EVERY  DAY  USE 
AND  CIVIL  GOVERNMENT  MADE  PLAIN 

By  HENRY  SLADE  GOFF,  Author  of  the  Goff's.  Historical  Maps. 


113  pages,  illustrated,  cloth,  50c., 


There  has  long  been  a  demand  for  an  accurate  Rules  of  Order  text 
that  was  brief  yet  sufficiently  complete  for  all  practical  needs.  This 
is  such  a  book.  The  matter  is  so  clear,  so  well  arranged,  and  so  suc- 
cinct that  those  interested  in  social  centers,  clubs,  societies,  etc.,  will 
be  delighted  with  it.  The  book  also  presents  the  main  points  of  civil 
government  that  everyone  ought  to  know. 


OTHER  STANDARD  AGRICULTURAL  BOOKS 


AGRICULTURE  FOR  YOUNG  FOLKS 

By  A.  D.  WILSON  and  E.  W.  WILSON. 


A  thoroughly  practical  treatise  on  Elementary  Agriculture  dealing 
with  the  e very-day  problems  of  the  farm. 

This  book  avoids  the  vague  generalities  and  scientific  theories 
and  treats  each  subject  in  a  manner  easily  understood  and  readily 
applied  to  existing  conditions  on  every  farm.  Prepared  especially  for 
beginners  and  contains  many  valuable  suggestions  which  would  prove 
interesting  to  the  most  experienced  farm  manager.  Among  the  numer- 
ous subjects  discussed  are:  Preparing  the  Soil;  Seeding;  Rotation; 
Care  of  Crops;  Marketing;  Farm  Business;  Management  of  Cattle; 
Roads;  etc.,  etc.  Over  300  pages  profusely  illustrated.  Price,  $L00 
postpaid. 


AMATEUR  FRUIT  GROWING,  by  Samuel  B.  Green.  A 
practical  guide  to  the  growing  of  fruit  for  home  use  and  the  market, 
written  with  special  reference  to  cold  climates.  Illustrated.  134  pp. 
Price,  12  mo.  paper,  25  cents;  cloth,  50  cents. 

ELEMENTS  OF  AGRICULTURE,  by  H.  J.  Shepperd  and  J.  C. 
McDowell:  A  complete  treatise  on  practical  agriculture,  covering  plant 
and  animal  breeding;  thoroughly  illustrated.  A  complete  text  book, 
adopted  in  public  and  agricultural  schools  throughout  the  Northwest. 
12  mo.,  cloth,  100  pp.     Price,  $1.00. 

WEEDS  AND  HOW  TO  ERADICATE  THEM,  by  Thomas 
Shaw,  giving  the  names  of  the  most  troublesome  weed  pests  east  and 
west  and  successful  methods  of  destroying  them.  Price,  16  mo.,  210 
pp.,  cloth,  50  cents;  paper,  25  cents. 

FARM  BLACKSMITHING.  A  complete  treatise  on  black- 
smithing  by  J.  M.  Drew.  Written  for  farmers  who  want  a  workshop 
where  they  can  profitably  spend  stormy  days.  Illustrated,  100  pp. 
Price,  12  mo.,  cloth,  50  cents. 

STANDARD  BLACKSMITHING,  HORSESHOEING  AND 
WAGON  MAKING,  by  J.  G.  Holmstrom,  author  of  ''Modem  Black- 
smithing,  "  gives  practical  instructions  by  a  successful  blacksmith.  The 
latest  and  most  complete  book  on  the  subject  pubhshed.  Thoroughly 
illustrated.     Price,  12  mo.,  cloth,  $1.00. 

GRASSES  AND  HOW  TO  GROW  THEM,  by  Thomas  Shaw. 
Discusses  the  economic  grasses  fo  the  United  States  and  Canada  from 
the  standpoint  of  the  farmer  and  the  stockmen.  Price,  450  pages,  cloth, 
$1.50  postpaid. 


WEBB  PUBLISHING  CO.  ST.  PAUL.  MINN. 


\ 


AN  INITIAL  FINE  OF  25  CENTS 

THIS  BOOK  ON  THE  ^^^^  ^^  FOURTH 

OVERDUE. 


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